Again you have heard that it was said to them of old, Thou shalt not forswear thyself: but thou shalt perform thy oaths to the Lord.

“You have heard that it was said to the ancients: you shall not commit adultery, and so on. Above, he ordered the irascible appetite with respect to its passion; here he orders the concupiscible appetite with respect to the passion which is in its root, namely in the generative power. Now two things are set down here: first, the ordering of the concupiscible appetite as regards its motion; second, the confirmation of marriage itself, given as a remedy for it, at the place: whoever shall have put away his wife. Moreover in the first, he first warns against the disordered motion of concupiscence; second, he removes the occasion or provocation to it, at the place: but if thy right eye scandalize thee. The first contains two things, namely the justice of the old law, which consisted only in the external work; then the explanation of the new justice, which consists also in the internal, at the place: but I say to you, and so on. He says therefore, you have heard that it was said to the ancients, that is, to the Jews living under the precepts of the law a long time now elapsed. Hence Chrysostom: by saying to the ancients, he shows the great length of time since they received this commandment — you shall not commit adultery, that is, you shall not unlawfully mingle with a woman. For adultery properly is the illicit commingling of a man and a woman. Here Chrysostom asks why he does not speak of the first commandment. Response: because he begins from the most general passions, as was said above. But I say to you, that is, in addition to this commandment, which you think must be kept only in act, I add and explain that it must be kept also in the will, according to Augustine. For whoever shall have looked upon a woman, that is, whoever shall have fixed his gaze upon a woman. Now there is a question here, why, besides the other senses, he names only sight. Response: because sight is more ready at hand. Or, according to Bede, by sight he understands every movement of the mind toward delight. Likewise it is asked here, why he does not say, shall have desired, but whoever shall have looked. Response: because to desire is sometimes sudden and not deliberate, and thus it is venial, and is a propassion according to Jerome; but to look with a view to desiring involves deliberation, and therefore it is mortal, and is a passion according to Jerome. In connection with this it is asked, why he does not say to commit adultery, but only to desire her. Response: so as to give one to understand that not only the operation, or the consent to the operation, is damnable, but also the intention or the consent to the delighting. To desire her: according to Augustine and Jerome, that is, so as to look upon her with this end, that he may desire her inwardly, as he would do if the opportunity offered itself. He has already committed adultery with her in his heart, that is, he is guilty of adultery, because he has already passed over into the affection of the heart, according to Rabanus. Gregory: it is not lawful to gaze upon what it is not lawful to desire. Lamentations 3:51: my eye has preyed upon my soul. According to Augustine, under the name of those committing adultery he understands every carnal delight; and when he says shall have looked, sight is put for every movement that tends toward delight, not only bodily but also interior, which is in concupiscence, as Bede says. But if thy eye, and so on. Here he removes the things that provoke to that very motion, which are principally two, namely sight and touch. He removes the first when he says, but if thy right eye scandalize thee; then the second, at the place, and if thy right hand scandalize thee. He says therefore, but if thy right eye scandalize thee; as if to say: above I forbade you adultery in act and in will, but I forbid even more, namely every occasion provoking to it; hence I say, but if thy right eye, and so on. This is expounded in many ways by the saints. According to Jerome, Bede, and Hilary: by eye he means sight and the affection of the mind; hence Jerome: because above he had spoken of desire for a woman, he now rightly calls thought also — turning the sense toward diverse things — the eye. And Hilary: by the eye, and the right eye, is understood the affection of any minds whatsoever. According to Augustine, Rabanus, and Chrysostom, the right eye can here be taken for friends and counselors, who as it were point out the way in matters to be done. Hence Chrysostom: he added right, that you may learn that the discourse is not about members, but about those who have dealt familiarly with us. Likewise, according to Augustine, Bede, and Jerome, the right eye can be taken for parents and relatives. Or, according to one Gloss, for the contemplative life. It is to be understood, then, thus: if thy eye, that is, sense and thought, right, that is, under the appearance of good intention, scandalize thee, by desiring unlawfully, pluck it out, that is, by breaking its evil use, and cast it from thee, that is, by annihilating it entirely. Hence Chrysostom: there was a religious woman, and I looked upon her, and said, I ought to visit her assiduously, that I may instruct her, and confirm her in good: this regard is good, and is the right eye. But while I visited assiduously, I fell into the snare of desire for her; behold, a good regard, and the right eye, became to me an occasion of scandal. I shall therefore cast away that good regard, which is about to generate evil. And he concludes below: therefore every good which scandalizes us, or others, we ought to cut off from ourselves. Likewise if the right eye, that is, a friend and counselor in divine matters, scandalize, by drawing into heresy, such a one is to be plucked out by reproving him, cast away by openly contradicting him. Likewise if parents scandalize, by hindering holiness of life, such an eye is to be plucked out by resisting, cast away by separating oneself from them. Likewise if the contemplative life scandalizes, by turning into tedium or arrogance, it is to be plucked out at times by diminishing it, cast away by passing over into the active life. For it is expedient for thee, that is, it is more necessary and useful for thee, that one of thy members perish, that is, such a sense, or counselor, or relative, or contemplation — hence the Gloss: that which you have as a member — than that thy whole body go into Gehenna, that is, than that thou be sent, wholly in soul and body, into hell. The Gloss: it is better to be saved with that cut off, than to be damned with it. On the contrary: according to the canons, whoever on such an occasion shall have cut off a member of himself is irregular. Moreover another Gloss of Chrysostom and Augustine: no member is commanded to be plucked out according to the letter. On the contrary: this is read to have been done in the Lives of the Fathers. Response to the first: that he does not intend that any member ought to be cut off for this reason; but he calls cutting off or plucking out the removing from oneself, through the effort of a devout labor, of the use or act of this kind, as was said above. To the second, which is objected from the Lives of the Fathers, the response is that this is excused by the Holy Spirit, by whose inspiration it is believed to have been done, as Augustine says of Samson in the book On the City of God; which is not otherwise excused, except because the Holy Spirit secretly commanded this, who through him worked miracles. And if thy right hand, that is, operation, or exterior touch with good intention; or a friend who ministers to thee in good things; or, according to Chrysostom, the right hand is the will of the soul, the left, the will of the body. This bodily hand, however, as the same author says, is the organ of that other hand. But it is asked, why he made no mention of the left eye and the left hand, since it happens that one can suffer scandal through that as well. Response: by removing the one which seemed to offer the lesser occasion, he removes also that which gives the greater occasion. Or, according to Chrysostom, that you may understand that he is not speaking of bodily members, but is speaking of familiars, or friends, as was said above. Scandalize thee, that is, be an occasion of thy ruin, or of scandal, cut it off, namely by dismissing it, or by fleeing it; hence Chrysostom: according to the letter, no member in man is commanded to be cut off, but through the effort of a devout labor, if it does harm, it is to be recalled, and removed, and even put far from oneself, so that it not even be held in memory. Hence he adds, and cast it from thee, that is, by abandoning it entirely. For it is expedient for thee that one of thy members perish, than that thy whole body go into Gehenna. The Gloss: that is, it is better for thee to be saved with that cut off, than to be damned with it. It was said, and so on. Here is set down the second point, namely the confirmation of marriage given as a remedy for concupiscence. Hence, since above he removed the unlawful commingling against the law of marriage, here he removes the unlawful separation of those joined in marriage; and by this the confirmation of marriage stands against the heretics. Now two things are said here: first, the permission of the law of Moses; second, the justice and prohibition of the new law, at the place, but I say to you. He says therefore, it was said: he does not say by whom, or to whom, signifying by this that those to whom this was said were as it were estranged from God, Deuteronomy 24:1, where Moses wrote that if a wife should not please her husband on account of some uncleanness, he should put her away. Whoever shall have put away his wife, that is, shall have wished to put her away; and this was permitted by Moses, not commanded; hence Mark 10:4: Moses permitted a bill of divorce to be written, and the wife to be put away. Let him give her a bill of divorce. This was commanded under this condition, if he should put her away. And in the bill of divorce, as they say, the cause of the divorce was written, and the dowry which he was giving her, and the license which she had to marry another. Hence, according to Chrysostom, he renounced her, so that it would not be in his power to return to her. It is asked here, however, why Moses permitted this, since it was not enjoined upon him by the Lord. Response according to Ambrose and Chrysostom: he permitted it, lest, out of hatred or some other cause held against the wife, a greater evil should occur, namely her killing. Hence Ambrose: for it is better to be separated, than that blood be shed out of hatred. But it should be noted that permission is manifold. First, of licit concession, as when a superior grants you leave to visit your parents. Second, of dispensation, when he permits what is not lawful for you otherwise, such as to eat meat. Third, of toleration, as when between two evils the lesser is permitted, lest the greater occur: and such was the permission of Moses. For he is said to have permitted it, because he tolerated it, lest they should commit a greater evil, namely homicide, as was said above. And therefore the Lord says that Moses commanded this because of the hardness of their hearts, below, chapter 19:8. And such a permission is not a sin on the part of the one permitting, because he does this so as to resist a greater evil. Fourth, of indulgence, when something is permitted whose opposite is better: just as the apostles permitted second marriages, 1 Corinthians 7:39, although widowed continence would be better. Fifth, of sufferance, as God permits evils to be done, that he may draw forth good things. But I say to you, and so on, that is, determining this, that a wife is not to be put away for just any cause; and it was tolerated by Moses, lest a greater evil occur, namely homicide. Thus I restrict and explain: because whoever shall have put away his wife, except for the cause of fornication, namely bodily fornication, of the man or of the woman, makes her commit adultery, because she marries another. And this is not marriage, but adultery; hence he adds, and whoever shall have married her that is put away, commits adultery, because she ought to remain unmarried, or be reconciled to her husband, as the Gloss says. But if he should put her away on account of the cause of fornication, as Augustine says, he himself does not make her commit adultery, but she does, whose is the guilt. Nor can the one putting her away, while she is living, marry another, as is touched on in 1 Corinthians 7:39. Note that whoever puts away, or repudiates his wife, does four evils, as Chrysostom says: because, as regards God, he exists a homicide; second, he puts away one who is not committing fornication; third, he makes her an adulteress; and fourth, he makes the one who receives her commit adultery. Likewise, the woman who commits adultery commits four sins: she disinherits her children, violates the faith, puts away her husband, and fornicates as a result of the adultery. On account of this it is said, Isaiah 50:1: where is the bill of divorce of your mother, with which I put her away? Ecclesiasticus 23:32: every woman who leaves her husband shall sin. Likewise note, on that phrase except for the cause of fornication, the Gloss of Augustine and Chrysostom: the cause of fornication is if the wife compels her husband to idolatry, or to avarice, or to other unlawful desires; for fornication is not only that of illicit intercourse, but generally whatever makes one stray from the law of God. Therefore spiritual fornication dissolves marriage. On the contrary, Jerome: if a woman sins against her own soul, she is not defiled as regards her husband: as if to say: because she sins only against her own soul, she has not sinned against her husband, and thus by this the marriage ought not to be dissolved. Response: the bond of marriage is considered in three ways: either as to mutual restraint, or as to the rendering of the carnal debt, or as to the cohabitation of mutual service. The first bond nothing dissolves except the death of one, or of both, because, the marriage having been consummated, the one cannot contract another marriage while the other lives. The second bond is dissolved in carnal fornication, yet with a distinction: for a certain spiritual fornication corrupts only the one committing it, such as pride, anger, and the like; another corrupts the one cohabiting with the sinner, such as heresy, or theft, and the like. As to the first way, therefore, the bond of cohabitation ought not to be dissolved. As to the second, it ought to be dissolved while that spiritual fornication persists, as if a wife should say she is unwilling to live with her husband unless he commits theft, or the like. Now there are six cases, which are contained in these verses: similar, prostituting, force, death, and believed appearance if it be converted, afterward he knows, he cannot send away. In these cases it is not lawful to put away a wife committing fornication. The first is similarity, that is, if the husband himself is convicted of fornicating; the second, prostitution, that is, if the husband himself prostitutes her; the third is violence, that is, when she is overpowered by another through violence, and this is understood of absolute violence, and not of that which is through fear; the fourth is believed appearance, that is, when she is known by another under the appearance of her own husband, whom she supposed to be her husband; the fifth is death, that is, when she probably believes her husband to be dead, and marries another, and upon her husband's return she immediately withdraws from the latter union; the sixth is conversion, that is, when a believing spouse is put away by an unbelieving one according to the rite of the latter's own sect, afterward, both having been converted to the faith, the Church compels him to receive her back; the seventh is reconciliation, that is, when he has reconciled her to himself after adultery was committed, or has kept her though she commits adultery publicly. In these cases the husband cannot send away, that is, put away, a wife committing fornication. And thus is understood the Gloss of Augustine and Chrysostom. It is asked here, moreover, whether the same reasoning holds for husbands, if they are put away by their wives for the cause of fornication. Response of Jerome: whatever is said to husbands redounds also to wives, for neither is an adulterous wife to be put away, and an adulterous husband to be kept; the laws of Caesar are one thing, those of Christ another; among the former, the reins of chastity are loosened for husbands, but with Christ, what is not lawful for women is equally not lawful for men, because the same servitude is judged under an equal condition. Likewise, on that phrase makes her commit adultery, it is asked why he does not say, and if the woman marries another, she commits adultery. Response: the woman, as Chrysostom says, is weak; therefore, through the threats which she makes against the husband who puts her away, he wishes to correct that man's folly. Just as one who has a prodigal son, in putting him away, rebukes those who make him such, and forbids them to consort with him, or to appear before him. Again you have heard that it was said to the ancients. Above, he ordered the irascible and the concupiscible appetites toward their passions; here he orders the rational power with respect to truth. Now truth is twofold, created and uncreated. He orders, therefore, the rational power toward uncreated truth through due reverence and honor; second, toward created truth through right interpretation, at the place, but let your speech be, yea yea, no no. In the first, two things are said. For first he sets down the justice of the law, which consists in two things, namely in the avoidance of perjury, and the fulfilling of an oath undertaken, at the place, but thou shalt render to the Lord thy oaths. Second, the justice of the Gospel, which consists in two things: in the prohibition of the frequent use of oaths, when he says, but I say to you, swear not at all; and in the explanation of the prohibition, when he says, neither by heaven, and so on. He says therefore, again you have heard that it was said to the ancients, thou shalt not forswear thyself, that is, thou shalt not commit perjury; hence Leviticus 19:12: thou shalt not swear falsely, lest thou pollute the name of thy God. Now Chrysostom asks why, passing over theft, he goes on to false witness. Response: because he who steals sometimes commits perjury, and not the converse, for he who is unwilling to lie, or to swear falsely, will never choose to steal, and by this he draws attention to it. Or it should be said that theft was punished in the law, but lying was not, and therefore, lest it be thought lawful, he here forbids it. But thou shalt render to the Lord thy oaths, Jerome: that is, if it should happen that you swear, you shall swear by the Creator, not by a creature. Hence he says to the Lord, not to an idol, or to a creature, because, as Chrysostom says, he who does not render his oaths to the Lord, but to the elements, sins in two ways: first, because he does not render to God his due; second, because he deifies that by which he swears, and thus commits idolatry. The Gloss of Jerome: just as he commanded victims to be sacrificed to God, lest they sacrifice them to idols, so to little ones it was granted to swear by God. Therefore if to little ones, this is not lawful for the perfect. On the contrary: the Apostle swore, Romans 1:9: God is my witness, and so on. And the angel, Apocalypse 10:6. Response: he calls little ones those who speak the truth, or the humble who fear God. Or, to little ones, that is, for the sake of little ones, that is, for the sake of these temporal things. But I say to you, that is, on the occasion of perjury I forbid oaths as well, commanding you not to swear at all, that is, for any cause whatsoever, or without a legitimate cause, because when one swears without cause, the attestation of the first truth is held in contempt, because it is assumed in vain, which is forbidden, Exodus 20:7: thou shalt not take the name of thy God in vain. On the contrary, Psalm 109:4: the Lord has sworn, and he will not repent; Hebrews 6:16: an oath for confirmation is an end of all controversy. Response: he forbids swearing at all, that is, continually. Or, at all, taken in the composite sense, that is, in every case. Now three things ought to be present in an oath: due matter, namely truth; due form, namely justice; and a right end: hence, according to Augustine, Gregory, and Origen, he did not forbid swearing altogether, but taught, on the occasion of perjury, what is more perfect. According to Alexander, this was commanded only to the apostles in the primitive Church, lest they be held imperfect. Or, when he says, swear not at all, the affection for swearing is forbidden, not the effect, as James 5:12: above all things, my brethren, swear not, that is, do not desire it. Hence Jerome: Christ forbids swearing altogether, lest anyone should desire an oath as though it were a good thing, and, by the constant practice of swearing, slip into perjury. Likewise Augustine, in the book On Lying, says: swear not at all, that is, as far as it is in you, do not love it, nor desire it with any delight. Likewise the same Augustine: swearing is not good, yet it is not evil, when it is necessary. On the contrary, Augustine in the sermon On the Danger of Swearing: false swearing is pernicious, true swearing is dangerous, no swearing is safe. If it is dangerous, therefore it is evil. Response: it is called dangerous with respect to the one swearing, not because it is evil, but because some condition of the oath can easily be omitted, which is threefold, according to that word of Jeremiah 4:2: thou shalt swear, as the Lord lives, in truth, in judgment, and in justice. He swears in truth who swears according to the truth of the matter and of conscience; in justice, who swears lawfully; in judgment, who swears for a sufficient cause. Neither by heaven. Chrysostom: he who swears by heaven deifies heaven, and by heaven he understands every higher natural creature. The Gloss: let us not swear by creatures. On the contrary: Joseph swore by the health of Pharaoh, Genesis 42:15. Response: he swore, knowing that his power and health were from God. Therefore it was not to swear by a creature, but by God, in whose hand is the health of all. For it is the throne of God; Isaiah, last chapter, 1: heaven is my seat. Nor by the earth, by which is understood every lower natural creature, for it is the footstool of his feet; Isaiah, ibid.: the earth is the footstool of my feet. And, as Augustine says, God is said to sit in heaven, and to tread the earth, not because he has his members so situated, but because in the body of the world the greatest appearance is that of heaven, the least that of earth; on account of which he is said to sit in heaven, because he shines forth in his great power. Then he comprehends artificial creation, saying, neither by Jerusalem. It was the custom of the Jews to swear by Jerusalem, and the temple, and things of this kind. Because it is the city of the great king; Psalm 76:14: what god is great like our God? Neither shalt thou swear by thy head. By this is understood every creature which is the same as ourselves. Augustine: when someone swears by my health, he pledges his own health to God. When by my sons, he pledges them to God, so that this may fall upon their head which proceeds from his mouth. Because thou canst not make one hair white or black, namely, naturally; as if to say, this is not your work, but God's. Hence Augustine: to swear by any creatures whatsoever is to call upon their Creator as witness. On account of all these things it is said, Ecclesiasticus 23:9: let not thy mouth be accustomed to swearing. Chrysostom: there is no one who swears frequently who does not sometimes commit perjury. But let your speech be, yea yea, no no. This is the second part, where he orders the rational power toward created truth through right interpretation, namely when truth is expressed in word, according as it is conceived in the mind. Hence he says, thus I forbade swearing even when it is necessary to speak. But let it be, that is: but, let your speech be, yea yea, that is, let your speech, having the reality of the thing, be, yea yea, that is, let it be uttered according to the truth of conscience; no no, that is, of a thing which is not, let it be uttered that it is not. Hence Rabanus: yea yea, no no — he says it twice, so that what you say with your mouth, you may confirm by your works; what you deny in words, you may not confirm by deeds. But that which is more than these is of evil, that is, that which is asserted, or denied, beyond the simple truth of the matter, as through an oath, is of evil: he does not say that it is evil, as Augustine says, but of evil, namely not of you, but from the weakness of the one compelling you to swear, or from unbelief. Hence note that it is lawful to swear for many causes. First, for confirming the truth to unbelievers, 2 Corinthians 1:18: God is faithful, for our word toward you was not yea and nay. Second, for restoring peace, as Jacob swore to Laban, Genesis 31:53. Third, for contracting friendship, Genesis 26:28: the men of Gerar said to Isaac: let there be an oath between us. Fourth, for manifesting the truth, Deuteronomy 19:15: in the mouth of two or three witnesses shall every word stand. Fifth, for keeping fidelity, 2 Kings 5:3: the elders of Israel came to the king, and he made a covenant with them. Sixth, for the acknowledgment of obedience and subjection: thus the men of Gilead swore to Jephthah. Seventh, for keeping the custom of the Church, as canons do: just as the sons of Israel swore that they would serve the Lord. And these seven causes are for the sake of introducing some good. Likewise there are two other causes for the sake of removing some evil, namely as one swears in the contesting of a lawsuit, that calumny may be put to rest; Hebrews 6:16: an oath for confirmation is an end of all controversy. The other cause is for purging infamy; Deuteronomy 21:1: when the body of a man slain shall be found, and it is not known who is guilty of the murder, the elders and the judges shall go out... and shall say: our hands did not shed this blood, nor did our eyes see it. Be merciful to thy people Israel, whom thou hast redeemed, O Lord.”

“We have here an exposition of the third commandment, which we are the more concerned right to understand, because it is particularly said, that God will not hold him guiltless, however he may hold himself, who breaks this commandment, by taking the name of the Lord in vain. Now as to this command, I. It is agreed on all hands that it forbids perjury, forswearing, and the violation of oaths and vows, Mat 5:33. This was said to them of old time, and is the true intent and meaning of the third commandment. Thou shalt not use, or take up, the name of God (as we do by an oath) in vain, or unto vanity, or a lie. He hath not lift up his soul unto vanity, is expounded in the next words, nor sworn deceitfully, Psa 24:4. Perjury is a sin condemned by the light of nature, as a complication of impiety toward God and injustice toward man, and as rendering a man highly obnoxious to the divine wrath, which was always judged to follow so infallibly upon that sin, that the forms of swearing were commonly turned into execrations or imprecations; as that, God do so to me, and more also; and with us, So help me God; wishing I may never have any help from God, if I swear falsely. Thus, by the consent of nations, have men cursed themselves, not doubting but that God would curse them, if they lied against the truth then, when they solemnly called God to witness to it. It is added, from some other scriptures, but shalt perform unto the Lord thine oaths (Num 30:2); which may be meant, either, 1. Of those promises to which God is a party, vows made to God; these must be punctually paid (Ecc 5:4, Ecc 5:5): or, 2. Of those promises made to our brethren, to which God was a Witness, he being appealed to concerning our sincerity; these must be performed to the Lord, with an eye to him, and for his sake: for to him, by ratifying the promises with an oath, we have made ourselves debtors; and if we break a promise so ratified, we have not lied unto men only, but unto God. II. It is here added, that the commandment does not only forbid false swearing, but all rash, unnecessary swearing: Swear not at all, Mat 5:34; Compare Jam 5:12. Not that all swearing is sinful; so far from that, if rightly done, it is a part of religious worship, and we in it give unto God the glory due to his name. See Deu 6:13; Deu 10:20; Isa 45:23; Jer 4:2. We find Paul confirming what he said by such solemnities (Co2 1:23), when there was a necessity for it. In swearing, we pawn the truth of something known, to confirm the truth of something doubtful or unknown; we appeal to a greater knowledge, to a higher court, and imprecate the vengeance of a righteous Judge, if we swear deceitfully. Now the mind of Christ in this matter is, 1. That we must not swear at all, but when we are duly called to it, and justice or charity to our brother, or respect to the commonwealth, make it necessary for the end of strife (Heb 6:16), of which necessity the civil magistrate is ordinarily to be the judge. We may be sworn, but we must now swear; we may be adjured, and so obliged to it, but we must not thrust ourselves upon it for our own worldly advantage. 2. That we must not swear lightly and irreverently, in common discourse: it is a very great sin to make a ludicrous appeal to the glorious Majesty of heaven, which, being a sacred thing, ought always to be very serious: it is a gross profanation of God's holy name, and of one of the holy things which the children of Israel sanctify to the Lord: it is a sin that has no cloak, no excuse for it, and therefore a sign of a graceless heart, in which enmity to God reigns: Thine enemies take thy name in vain. 3. That we must in a special manner avoid promissory oaths, of which Christ more particularly speaks here, for they are oaths that are to be performed. The influence of an affirmative oath immediately ceases, when we have faithfully discovered the truth, and the whole truth; but a promissory oath binds so long, and may be so many ways broken, by the surprise as well as strength of a temptation, that it is not to be used but upon great necessity: the frequent requiring and using of oaths, is a reflection upon Christians, who should be of such acknowledged fidelity, as that their sober words should be as sacred as their solemn oaths. 4. That we must not swear by any other creature. It should seem there were some, who, in civility (as they thought) to the name of God, would not make use of that in swearing, but would swear by heaven or earth, etc. This Christ forbids here (Mat 5:34) and shows that there is nothing we can swear by, but it is some way or other related to God, who is the Fountain of all beings, and therefore that it is as dangerous to swear by them, as it is to swear by God himself: it is the verity of the creature that is laid at stake; now that cannot be an instrument of testimony, but as it has regard to God, who is the summum verum - the chief Truth. As for instance, (1.) Swear not by the heaven; "As sure as there is a heaven, this is true;" for it is God's throne, where he resides, and in a particular manner manifests his glory, as a Prince upon his throne: this being the inseparable dignity of the upper world, you cannot swear by heaven, but you swear by God himself. (2.) Nor by the earth, for it is his footstool. He governs the motions of this lower world; as he rules in heaven, so he rules over the earth; and though under his feet, yet it is also under his eye and care, and stands in relation to him as his, Psa 24:1. The earth is the Lord's; so that in swearing by it, you swear by its Owner. (3.) Neither by Jerusalem, a place for which the Jews had such a veneration, that they could not speak of any thing more sacred to swear by; but beside the common reference Jerusalem has to God, as part of the earth, it is in special relation to him, for it is the city of the great King (Psa 48:2), the city of God (Psa 46:4), he is therefore interested in it, and in every oath taken by it. (4.) "Neither shalt thou swear by the head; though it be near thee, and an essential part of thee, yet it is more God's than thine; for he made it, and formed all the springs and powers of it; whereas thou thyself canst not, from any natural intrinsic influence, change the colour of one hair, so as to make it white or black; so that thou canst not swear by thy head, but thou swearest by him who is the Life of thy head, and the Lifter up of it." Psa 3:3. 5. That therefore in all our communications we must content ourselves with, Yea, yea, and nay, nay, Mat 5:37. In ordinary discourse, if we affirm a thing, let us only say, Yea, it is so; and, if need be, to evidence our assurance of a thing, we may double it, and say, Yea, yea, indeed it is so: Verily, verily, was our Saviour's yea, yea. So if we deny a thing, let is suffice to say, No; or if it be requisite, to repeat the denial, and say, No, no; and if our fidelity be known, that will suffice to gain us credit; and if it be questioned, to back what we say with swearing and cursing, is but to render it more suspicious. They who can swallow a profane oath, will not strain at a lie. It is a pity that this, which Christ puts in the mouths of all his disciples, should be fastened, as a name of reproach, upon a sect faulty enough other ways, when (as Dr. Hammond says) we are not forbidden any more than yea and nay, but are in a manner directed to the use of that. The reason is observable; For whatsoever is more than these cometh of evil, though it do not amount to the iniquity of an oath. It comes ek tou Diabolou; so an ancient copy has it: it comes from the Devil, the evil one; it comes from the corruption of men's nature, from passion and vehemence; from a reigning vanity in the mind, and a contempt of sacred things: it comes from that deceitfulness which is in men, All men are liars; therefore men use these protestations, because they are distrustful one of another, and think they cannot be believed without them. Note, Christians should, for the credit of their religion, avoid not only that which is in itself evil, but that which cometh of evil, and has the appearance of it. That may be suspected as a bad thing, which comes from a bad cause. An oath is physic, which supposes a disease.”

“Again, ye have heard that it hath been said,.... Besides what has been observed, in ver. 21 and 27 you know it has also been said, by, or to them of old time, what is written in Lev 19:12. "And ye shall not swear by my name falsely"; which seems to be referred to, when it is said, "thou shalt not forswear thyself": and is the law forbidding perjury, or false swearing; and was what the Jews were chiefly, if not only concerned about; little regarding the vanity, only the truth of an oath: for they took swearing vainly, to be the same as swearing falsely; wherefore so long as what they swore was truth, they were not careful whether it was of any importance or not: moreover, these men sinned, in that they swore by the creatures, which they thought they might do, and not sin; and when they had so done, were not under obligation to perform; because they made no use of the name of God, to whom only vows and oaths were to be performed, "but shalt perform unto the Lord thine oaths", Num 30:2 which they understood of vows only made to the Lord, and not to others; and of oaths, when in his name, and not by others; which they did do, and yet thought themselves not obliged by them.”

“Again, ye have heard that it hath been said by them of old time, Thou shalt not forswear thyself--These are not the precise words of Exo 20:7; but they express all that it was currently understood to condemn, namely, false swearing (Lev 19:12, &c.). This is plain from what follows. But I say unto you, Swear not at all--That this was meant to condemn swearing of every kind and on every occasion--as the Society of Friends and some other ultra-moralists allege--is not for a moment to be thought. For even Jehovah is said once and again to have sworn by Himself; and our Lord certainly answered upon oath to a question put to Him by the high priest; and the apostle several times, and in the most solemn language, takes God to witness that he spoke and wrote the truth; and it is inconceivable that our Lord should here have quoted the precept about not forswearing ourselves, but performing to the Lord our oaths, only to give a precept of His own directly in the teeth of it. Evidently, it is swearing in common intercourse and on frivolous occasions that is here meant. Frivolous oaths were indeed severely condemned in the teaching of the times. But so narrow was the circle of them that a man might swear, says LIGHTFOOT, a hundred thousand times and yet not be guilty of vain swearing. Hardly anything was regarded as an oath if only the name of God were not in it; just as among ourselves, as TRENCH well remarks, a certain lingering reverence for the name of God leads to cutting off portions of His name, or uttering sounds nearly resembling it, or substituting the name of some heathen deity, in profane exclamations or asseverations. Against all this our Lord now speaks decisively; teaching His audience that every oath carries an appeal to God, whether named or not. neither by heaven; for it is God's throne--(quoting Isa 66:1);”

“(non occ.) The Lord has hitherto taught to abstain from injuring our neighbour, forbidding anger with murder, lust with adultery, and the putting away a wife with a bill of divorce. He now proceeds to teach to abstain from injury to God, forbidding not only perjury as an evil in itself, but even all oaths as the cause of evil, saying, Ye have heard it said by them of old, Thou shall not forswear thyself. It is written in Leviticus, Thou shalt not forswear thyself in my name; (c. 19:12.) and that they should not make gods of the creature, they are commanded to render to God their oaths, and not to swear by any creature, Render to the Lord thy oaths; that is, if you shall have occasion to swear, you shall swear by the Creator and not by the creature. As it is written in Deuteronomy, Thou shall fear the Lord thy God, and shall swear by his name. (c. 6:13.)”