Jas 5:12

“What if someone swears an oath and claims that he was forced to do so? The fear of God is more powerful than any force. For though you may start out by swearing all kinds of promises, you will not keep any of them. Moreover, you would not dare to swear or give an oath in matters of human law, which you accept whether you want to or not. You would certainly never claim that you were forced into doing so. Now the person who has heard the blessings of God and who has prepared himself as Christ has commanded will never claim any need to do anything of the kind, for he is respected and honored by all. What is needed beyond a simple yes and no? An oath adds nothing to these, for no one has to be told that evil is the source of both excess and its deficient opposite. An oath is a form of excess.”

“Let the witness of our life be stronger than an oath, and if some shameless person dares to ask an oath from you, let your yes be yes and your no be no, instead of swearing an oath. James forbids us to swear by heaven or by earth for this reason, that we should not give the creation more value than it has by deifying it. For those who swear, swear by something greater than themselves, as the apostle says.”

“Jesus said: "Let your yes be yes and your no, no." Any more than this is evil. So do not swear for good reason, because that is evil. It is said to be evil because the need of an oath comes from an unsure conscience. It is necessary to extract an oath from one whose sincerity is in doubt, but why should you bind yourself by an involuntary oath when you are bound to show with your lips the sincerity of your heart? Speak the truth from your heart and you will not need an oath.”

“Let your affirmation be firm in firmness and your negation be the same. Otherwise: let the testimony of your life be firmer than an oath. If someone shameless, not respecting your life, insistently demands an oath from you, then instead of an oath let your "yes, yes" and "no, no" suffice. By hypocrisy he means either the condemnation that will befall those who swear recklessly and from the habit of swearing fall into perjury, or hypocrisy itself, which is one thing and appears another. In what way does the one who swears fall into hypocrisy? In the following way: as one who swears, he is regarded as affirming the truth, but when a violation of the oath follows, he turns out to be a liar. The apostle forbids swearing by God in order to avoid perjury, and by heaven and other objects — so as not to attribute to them the honor due to God, for all who swear, swear by what is greater (Heb. 6:16). But someone will say: what should one do if a person is compelled to swear? We answer: the fear of God is stronger than the compulsion of the one forcing him. Another, having in mind the Old Law, will also be perplexed: if the Old Law approves of one who swears by the name of the Lord, then how does grace forbid doing this? We answer: the Old Law commanded the Jews to swear by God in order to turn them from swearing by idols, just as it commanded them to offer sacrifices to God in order to divert them from offering sacrifices to idols. But when it had sufficiently taught the Jews piety, it then abolished sacrifices as useless and began to require as a sacrifice not the slaughter of animals, but a contrite soul. What kind of soul is this? One that through humility is entirely consumed by the fire of love, like Paul, who burned most intensely when some of the faithful were caused to stumble (2 Cor. 11:29).”

“But above all things….swear not, &c. This earnest admonition is against all kind of oaths in common conversation, (not against oaths made on just and necessary occasions) and in the very same words, as our blessed Saviour warned all people against this sin of swearing. (Matthew, chap. v.) How unaccountably is this commandment of God contemned? And what a dreadful account will some day be exacted for so many oaths, curses, and blasphemies, which are now so common, that we may rather wonder at the patience of God and that already exemplary punishments have not fallen upon whole cities and kingdoms for this continued profanation of the holy name of God? (Witham) — St. James here repeats the injunctions of our Saviour, not to swear al all. (Matthew v. 34.) See the annotations in that place.”

“But above all--as swearing is utterly alien to the Christian meek "endurance" just recommended. swear not--through impatience, to which trials may tempt you (Jam 5:10-11). In contrast to this stands the proper use of the tongue, Jam 5:13. James here refers to Mat 5:34, &c. let your yea be yea--Do not use oaths in your everyday conversation, but let a simple affirmative or denial be deemed enough to establish your word. condemnation--literally, "judgment," namely, of "the Judge" who "standeth before the doors" (Jam 5:9).”

“But above all, my brothers, do not swear, neither by heaven, nor by earth, nor by any other oath. But let your yes be yes, and your no be no, so that you do not fall into hypocrisy. But someone will say: If someone is compelled to swear, what should be done? We say that the fear of God will be stronger than the necessity imposing force. However, someone might doubt, since the old law holds that those who swear by the name of the Lord are worthy of praise, how does grace forbid this? Therefore, we say that the old law, leading the Jews not to swear by idols, commanded them to swear by God: just as it also commanded them to sacrifice to God, withdrawing them from sacrificing to idols: where it sufficiently taught the worship of God, then it also rejected sacrifices as useless: not seeking the sacrifice of animals, but a repentant soul as a sacrifice. But what is that? It is one that is entirely set ablaze with the fire of love through the modesty of the spirit, such as was also the soul of Paul, who, because some of the faithful were offended, was wondrously kindled. "But let your yes be yes." This means your deposit should be firm and reaffirmed, and denial in those things that do not correspond to the act. "That they may not fall into hypocrisy." The term hypocrisy refers to condemnation, that is, the condemnation that follows those who incessantly and without selection swear: and by the habit of swearing, they are led to perjury. Or even the term hypocrisy in this context has a specific meaning (for example, simulation) which is different from what it appears. How then does one who swears fall into hypocrisy? For in swearing, one is believed to be truthful, but by subsequent transgression, he is found to be lying instead of truthful. Or also because ναὶ, that is yes, is not presented for confirmation, nor is οὐ, that is no, in response to what does not correspond to the act. However, swearing by God is prohibited because of perjury; but swearing by heaven and the rest, so that these may not be referred to divine honor. For whoever swears, swears by the greater.”