The interpretation timeline
Romans 16:19 Douay-Rheims

For your obedience is published in every place. I rejoice therefore in you. But I would have you to be wise in good, and simple in evil.

A.D. 215 – 1871 7 witnesses

Patristic

before A.D. 750
215
A.D.
c. A.D. 150–215
“The ancient race was perverse and hard-hearted; but the band of infants, the new people which we are, is delicate as a child. On account of the hearts of the innocent, the apostle, in the Epistle to the Romans, owns that he rejoices, and furnishes a kind of definition of children, so to speak, when he says, "I would have you wise toward good, but simple towards evil." On account of the hearts of the innocent, the apostle, in the Epistle to the Romans, owns that he rejoices, and furnishes a kind of definition of children, so to speak, when he says, "I would have you wise toward good, but simple towards evil." ...But if, which is rather the true sense, they themselves understand the designation children of simple ones, we glory in the name. For the new minds, which have newly become wise, which have sprung into being according to the new covenant, are infantile in the old folly.”
Source
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“"For your obedience is come abroad unto all men." This he does, not to leave them free to be shameless, but to win them beforehand with encomiums, and the number of his witnesses, to arrest their attention. For neither is it I alone that am the witness, but the whole world. And he does not say for your understanding, but, "your obedience:" that is, their compliance, which was evidence of much meekness in them. "I am glad therefore on your behalf." And this is no small encomium too. Then, after the praise, admonition. For lest, after liberating them from any charges against them, he should make them the more listless, as not being observed; he gives them another hint in the words, "I would have you wise unto that which is good, and simple concerning evil." You see then how he attacks them again, and that without their suspecting it. For this looks like intimating that some of them were apt to be led astray.”
Source

Scholastic

c. 1100 – 1500
1273
A.D.
Thomas Aquinas Catholic
1225–1274
“After the Apostle has enjoined whom they should greet, he here shows them whom they ought to avoid. And concerning this he does three things. First, he teaches whom they ought to avoid; second, he assigns the reason, at the words for such men, etc.; third, he promises them divine help for accomplishing this, at the words and the God of peace, etc. And because those whom he wished to be avoided proceeded fraudulently, deceiving under the appearance of piety, according to that word of Matthew 7:15: they come to you in sheep's clothing, but inwardly they are ravening wolves, therefore, first, he leads them to exercise caution, saying now I beseech you, brethren, to mark them which cause dissensions and offenses contrary to the doctrine which you have learned. Here, first, it should be considered that "to observe" is nothing other than to consider diligently, which indeed is sometimes taken in a good sense, sometimes in a bad sense. It is taken in a bad sense when someone diligently considers the condition and course of another in order to harm him, according to that word of Psalm 36:12: the sinner shall observe the just man, and shall gnash upon him with his teeth. And in Luke 14:1 it is said: and they watched him. It is taken in a good sense, in one way, when someone considers the precepts of God in order to do them. Exodus 23:21: observe therefore and hear his voice. In another way, when someone diligently considers good men in order to imitate them, according to that word of Philippians 3:17: be followers of me, brethren, and mark them which walk so, as you have us for a pattern. Third, evil men are observed in order to be avoided, and it is taken in this sense here. For there were certain men converted to the faith from among the Jews, who preached that the precepts of the law were to be observed, and from this, first, dissensions and sects followed in the Church, while some of them adhered to the error and others persisted in the true faith. Galatians 5:20: dissensions, sects, etc. Second, offenses and scandals followed, of which it was treated above in chapter 14, while some judged others and others despised others — these are the ones who cause dissensions and offenses. Isaiah 57:14: take away the stumbling-blocks out of the way of my people. Now he says contrary to the doctrine which you have learned from the true apostles of Christ, in order to show that such dissensions and scandals arose from the falsity of their teaching. Galatians 1:9: if any man preach any other gospel unto you than that which you have received, let him be anathema. Second, he warns that, once recognized, they should be avoided, saying and avoid them, that is, flee their doctrine and their company. Psalm 118:115: depart from me, you malignant ones, and I will search the commandments of my God. Then when he says for such men, etc., he assigns two reasons for what he had said, of which the first is taken from the side of those whom he wishes to be avoided. And first he describes their intention, saying for such men do not serve our Lord Christ, but their own belly. For they did not preach for the glory of Christ, but for gain, so as to fill their own belly. Philippians 3:18: many walk, of whom I have told you often, and now tell you even weeping, that they are the enemies of the cross of Christ, whose God is their belly. Second, he describes their deception, saying and by good words and fair speeches deceive the hearts of the innocent, that is, of the simple and unlearned. Proverbs 14:15: the innocent believeth every word. By good words, in which they pretend to sanctity, according to that word of Psalm 27:3: who speak peace with their neighbor, but evils are in their hearts. And fair speeches, namely by which they bless and flatter those who follow them. Isaiah 3:12: O my people, they that call thee blessed, the same deceive thee. Malachi 2:2: I will curse your blessings. He assigns the second reason from the condition of the Romans, who showed themselves ready to follow after both good and evil. Hence, first, he commends them for their readiness for good, saying for your obedience, by which you readily obeyed the faith, is come abroad unto all men, because of the dominion which the Romans then held over the other nations. Hence what was done by the Romans was readily spread abroad to others. Above, in chapter 1:8: your faith is spoken of throughout the whole world. I am glad therefore on your behalf, namely because you have obeyed the faith, and this in charity, of which it is said in 1 Corinthians 13:6, that it rejoiceth not in iniquity, but rejoiceth with the truth. Second, he makes them cautious against evil, saying but yet I would have you wise unto that which is good, namely that you cleave to that which is good — 1 Thessalonians, the last chapter: hold fast that which is good — and simple concerning evil, namely lest through some simplicity you decline toward evil, so that your simplicity may be such that you deceive no one unto evil. Matthew 10:16: be ye wise as serpents, and simple as doves. Conversely, of certain men it is said in Jeremiah 4:22: they are wise to do evil, but to do good they have no knowledge. Then when he says and the God of peace, etc., he promises them divine help against such deceivers. And first the promise is set down, when he says and the God of peace, that is, its author, who hates the dissensions that these men cause, shall bruise Satan, that is, the Devil who through these pseudo-apostles strives to deceive you, under your feet, because indeed you will conquer him through your wisdom. And this shall happen shortly, namely at my coming. Luke 10:19: behold, I give unto you power to tread on serpents and scorpions, and over all the power of the enemy. Malachi, the last chapter: you shall tread down the wicked, when they shall be as ashes under the sole of your feet. Second, the prayer for obtaining this is set down, when he says the grace of our Lord Jesus Christ be with you, which indeed suffices to protect you. 2 Corinthians 12:9: my grace is sufficient for thee. Then when he says Timothy my workfellow saluteth you, etc., he greets them on behalf of others, saying Timothy my workfellow saluteth you, namely in the preaching of the Gospel. 1 Corinthians 4:17: I have sent unto you Timotheus, who is my beloved son, and faithful, etc. He adds, moreover, and Lucius, and Jason, and Sosipater, my kinsmen, who were Jews, greet you, namely. Now there was a certain notary of Paul named Tertius, to whom Paul granted that he should greet the Romans in his own person. Hence it is added I Tertius, who wrote this epistle, salute you in the Lord. Then he says Gaius mine host saluteth you, to whom the third canonical epistle of John is addressed, in which he is commended for the charity which he showed to the saints. And of the whole church, namely which was gathered in his house, or which was in that province. Then he says Erastus the chamberlain of the city saluteth you, namely he who kept the common chest, that is, the common revenues of the city, and Quartus a brother, that is, a believer, by name Quartus. Then he greets them on his own behalf, saying the grace of our Lord Jesus Christ be with you all. Amen. And he ends the epistle with an act of thanksgiving, saying now to him, namely to God who is the Trinity, that is of power to establish you — 1 Peter, the last chapter: after that ye have suffered a while, he himself shall perfect, confirm, and establish you — and this in the faith which is according to my Gospel, that is, according to the Gospel which I preach. 1 Corinthians 15:11: whether it were I or they, so we preach, and so ye believed. And also according to the preaching of Jesus Christ, who first preached the Gospel, according to that word of Hebrews 2:3: which at the first began to be spoken by the Lord. Hence it is said in Matthew 4:23, that Jesus went about preaching the gospel of the kingdom. Now it is added, according to the revelation of the mystery, that is, of the secret, which indeed can be referred to what he had said above, according to my Gospel; or because in the Gospel itself the secret of the divine incarnation is revealed, according to that word above in chapter 1:17: the righteousness of God is revealed therein; or because to the Apostle himself the Gospel was revealed. 1 Corinthians 2:10: but unto us God hath revealed them by his Spirit. Concerning this secret it is said in Isaiah 24:16: my secret to myself. Or this may better be referred to what he had said, to establish, as if he were saying: God can establish you in my Gospel and preaching, and this according to the revelation of the mystery, that is, of the secret, namely concerning the conversion of the Gentiles, as is found in Ephesians 3:8 and following: unto me, who am less than the least of all saints, is this grace given, that I should preach among the Gentiles, and make all men see what is the dispensation of the mystery, etc. Hence he also adds since the world began, because indeed it was hidden among men that the Gentiles were to be converted to the faith. Now he calls these times eternal as if long-enduring, because from the beginning of the world this was hidden, as also is said in Psalm 75:4: thou, enlightening wonderfully from the everlasting mountains. And it can be said that the eternal times are called eternity itself, of which it is said in Isaiah 57:15: the high and eminent one, inhabiting eternity, so that just as the simple essence of God is described by a certain likeness through corporeal dimensions, according to that word of Job 11:9: the measure thereof is longer than the earth, and broader than the sea, so also his simple eternity is designated through eternal times, insofar as it contains all times. Now he adds that, namely the mystery, is now made manifest, concerning the conversion of the Gentiles, by the scriptures of the prophets, that is, according as the prophets foretold, as was made clear above in chapter 15. Hence in Ephesians 3:5 and following it is said: which in other ages was not made known unto the sons of men, as it is now revealed unto his holy apostles and prophets by the Spirit, that the Gentiles should be fellow-heirs, etc. Now it is made manifest through the fulfillment of the work by the command of God. Hence according to the commandment of the everlasting God, who indeed by his eternal purpose does in time the things which he wills, which command of God indeed is made known to all nations for the obedience of faith, that is, that all nations may obey the faith. Above, in chapter 1:5: for obedience to the faith among all nations. But if we speak of the mystery of the incarnation, the text is to be construed thus: of the mystery, I say, kept secret since the world began, because before it was not so manifest. Which mystery, I say, is now made manifest by the scriptures of the prophets, who foretold this according to the commandment of the everlasting God, who willed the mystery of the incarnation to be made manifest, and this for the obedience of faith among all nations. Of the mystery, I say, although kept secret among men, yet known only to God who is wise, because he alone knew this, and those to whom he willed to reveal it, because, as it is said in 1 Corinthians 2:11: the things of God knoweth no man, but the Spirit of God. Or it can be understood of him who alone is wise, namely by essence, as is said in Matthew 19:17 and Mark 10:18: none is good, save one, that is, God. Nor is the Son excluded by this, because the perfection of the whole Trinity is the same, just as, conversely, it is said: no man knoweth the Father, save the Son, Matthew 11:27 — the Father is not excluded from knowledge of himself. Now he adds by Jesus Christ; which is not to be understood in this sense, that God the Father is wise through Jesus Christ, because since for God to be wise is the same as to be, it would follow that the Father exists through the Son, which is unfitting; but this is to be referred to what he had said above: is now made manifest, namely through Jesus Christ. To whom, that is, to Jesus Christ, be honor and glory, through the reverence of the whole creature, according to that word of Philippians 2:10: at the name of Jesus every knee should bow. And glory, namely as to the fullness of his divinity, just as it is added there: and every tongue should confess that the Lord Jesus Christ is in the glory of God the Father. And this not for a time, but for ever, world without end. Hebrews, the last chapter: Jesus Christ, the same yesterday, and today, and forever. He adds, moreover, for the confirmation of the truth: Amen. Or it can be construed thus: known only to the wise God, to whom, through Jesus Christ, is glory — who glorified God, according to that word of John 17:4: I have glorified thee on the earth. Now it should be noted that this construction is defective, and is to be supplied thus: to him who is able, etc., be honor and glory through Jesus Christ, to whom is honor and glory. But if the word "to whom" is not there, the construction will be straightforward.”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“And the God of peace,.... See Gill on Rom 15:33; shall bruise Satan under your feet shortly. Some read this by way of wish or prayer, "may the God of peace bruise"; so the Vulgate Latin, Syriac, and Ethiopic versions, and the Alexandrian copy; but others as ours, as a promise, or as expressive of the apostle's faith and hope in this matter; and which he mentions to encourage the members of this church to be upon their guard, and make head against these false teachers; since in a little time they might be assured of victory over Satan and these his emissaries: as it is before suggested, that the methods these men used to beguile weak minds were much like those that Satan used when he attacked our first parents, so here is a manifest allusion to what was said by way of threatening to him, "it", the woman's seed, "shall bruise thy head", Gen 3:15; and which has had its accomplishment in Christ, who has not only destroyed the works of the devil, but him himself, and spoiled his principalities and powers, and bruised him and them under his feet, when he led captivity captive; and though, for the trial of the graces of his people, Satan is permitted to attack them in various shapes, yet in a short time he will be bruised under their feet, as he is already under their Lord and master's. The apostle refers not so much to his coming among them in a short time, when he might hope and believe that he should be an instrument of crushing these men Satan made use of, of quelling the contentions they raised, and putting a stop to the divisions they made, and under the influence, and by the assistance of the God of peace, restore them to their former peace and tranquillity, though it is a sense not to be despised; much less does he refer to the destruction of Jerusalem, which was to be in a very short time, when the crucifiers of Christ and the persecutors of the saints would have the wrath of God come upon them to the uttermost, since these Romans had no great and immediate concern with them; nor does he regard the spread of the Gospel in the Gentile world, whereby Satan fell as lightning from heaven, and was cast out of the idol temples, for this was greatly fulfilled already: but rather he refers to the time of Constantine, when Satan's seat at Rome was overturned, when he was cast down from his throne and trampled under feet, who had deceived the whole world, the whole Roman empire, when the Gospel triumphed over its secret and open enemies, profane persecutors, and perfidious teachers, over idolatry and superstition on the one hand, and error and heresy on the other, though this did not last long; wherefore some have thought the apostle refers to the latter day, when Satan shall be bound a thousand years, or to the last of all, when he shall be for ever under the feet of the saints, and never be able to give them any more trouble; and this the apostle might say would be shortly, since the second coming of Christ was expected to be quickly: yea, this may be applied to the case of every believer now, and be for his encouragement to be vigilant and on his guard against Satan, to resist him, repel his temptations, and oppose his emissaries; since he may assure himself he shall be more than a conqueror over him through Christ, that has loved him, and that in a very little time, when death comes, and he shall enter into the joy of his Lord, where he will be out of the reach of Satan, and unmolested by him. The grace of our Lord Jesus Christ be with you, Amen: to enable you to abide by the truth; to mark and avoid the authors of sects, and causes of divisions, and offences; to oppose error and defend truth; to keep from falling, to stand against every assault of Satan, and to bear up under every temptation of his; to get the victory over him, and to preserve them safe to the kingdom and glory of Christ.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“For your obedience is come abroad - The apostle gives this as a reason why they should continue to hear and heed those who had led them into the path of truth, and avoid those false teachers whose doctrines tended to the subversion of their souls. Yet I would have you wise - I would wish you carefully to discern the good from the evil, and to show your wisdom, by carefully avoiding the one and cleaving to the other.”
Source
1863
A.D.
1796–1863
“As their faith, so also their docility and obedience were celebrated. Their confiding piety might expose them to the wiles of artful men.”
1871
A.D.
1871
“For your obedience--that is, tractableness is come abroad unto all. I am glad therefore on your behalf--"I rejoice therefore over you," seems the true reading. but yet I would have you wise unto that which is good, and simple--"harmless," as in Mat 10:16, from which the warning is taken. concerning--"unto" evil--"Your reputation among the churches for subjection to the teaching ye have received is to me sufficient ground of confidence in you; but ye need the serpent's wisdom to discriminate between transparent truth and plausible error, with that guileless simplicity which instinctively cleaves to the one and rejects the other."”
Source
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.