The interpretation timeline
Romans 4:2 Douay-Rheims

For if Abraham were justified by works, he hath whereof to glory, but not before God.

A.D. 407 – 1871 7 witnesses

Patristic

before A.D. 750
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“He had said that the world had become guilty before God, and that all had sinned, and that boasting was excluded and that it was impossible to be saved otherwise than by faith. He is now intent upon showing that this salvation, so far from being matter of shame, was even the cause of a bright glory, and a greater than that through works. For since the being saved, yet with shame, had somewhat of dejection in it, he next takes away this suspicion too. And indeed he has hinted at the same already, by calling it not barely salvation, but "righteousness. Therein" (he says) "is the righteousness of God revealed." For he that is saved as a righteous man has a confidence accompanying his salvation. And he calls it not "righteousness" only, but also the setting forth of the righteousness of God. But God is set forth in things which are glorious and shining, and great. And he calls him "father, as pertaining to the flesh," to throw them out of the genuine relationship to him, and to pave the Gentiles' way to kinsmanship with him. And then he says, "For if Abraham were justified by works, he hath whereof to glory: but not before God." After saying that God "justified the circumcision by faith and the uncircumcision through faith," and making the same sufficiently sure in what he said before, he now proves it by Abraham more clearly than he promised, and pitches the battle for faith against works, and makes this righteous man the subject of the whole struggle. For the great power of Paul is especially displayed in this, that he turns what is objected to the other side, and shows that what seemed rather to be on the side of salvation by works, viz. glorying or boldness of claim belonged much more truly to that by faith. For he that glorieth in his works has his own labors to put forward: but he that finds his honor in having faith in God, has a much greater ground for glorying to show, in that it is God that he glorifieth and magnifieth.”
Source
430
A.D.
Augustine of Hippo Patristic
A.D. 354–430
“Since Abraham without the law obtained glory not by the works of the law (as if he could fulfill the law in his own strength), since the law had not yet been given, the glory belongs to God, not to him. For he was justified not by his own merit, as if by works, but by the grace of God through faith.”

Scholastic

c. 1100 – 1500
1273
A.D.
Thomas Aquinas Catholic
1225–1274
“After the Apostle excluded the glory of the Jews which they had in the law, by which they preferred themselves to the Gentiles, here he excludes their glory as regards circumcision. And concerning this he does two things. First he resumes the question which he had proposed above, saying, What is the profit of circumcision? And because Abraham was the first to receive the commandment concerning circumcision, as is said in Genesis 17:10, therefore he repeats the question in the person of Abraham himself, saying: if it is so that God justifies the uncircumcision just as He justifies circumcision, what then shall we say that Abraham our father found according to the flesh? That is, according to carnal circumcision and according to the other carnal observances? It seems to be unfitting if it should be said that he found no profit, since it is said in Isaiah 47:17: "I am the Lord teaching you profitable things." Second, where he says "For if Abraham," etc., he responds to the question proposed. And he does two things. First he shows that Abraham did not find this through circumcision and the other works of the law, namely that he should be justified by it, but rather through faith. Second he commends his faith, where he says "who against hope," etc. Concerning the first he does two things. First he shows the proposition by an argument taken from the side of the divine acceptance; second, by an argument from the divine promise, where he says "For not through the law," etc. Concerning the first he does three things. First he proposes a certain conditional; second he proves the destruction of the consequent, where he says "For what does Scripture say," etc. Third, he proves the conditional itself, where he says "as also David," etc. Concerning the first part, the Apostle intends to argue thus: if Abraham had been justified by the works of the law, he would not have glory before God; therefore he was not justified by works. He proposes therefore a conditional, saying: it was asked what Abraham found according to carnal circumcision, and it is manifest that he did not find this — that he should be justified by the works of the law — in the sense, namely, that his justice should consist in the works of the law; he has glory indeed, namely before men, who see external deeds, but not before God, who sees in secret, according to that saying in 1 Kings 16:7: "But God looks upon the heart." 1 Corinthians 3:21: "Let no one of you glory in men," etc. Whence against certain ones it is said in John 12:43: "They loved the glory of men more than the glory of God." But against this it can be objected, because from the habit of external works an interior disposition is generated, according to which even the heart of man is well disposed, so that it is prompt for acting well and delights in good works, as the Philosopher teaches in Book II of the Ethics. But it must be said that this holds in human justice, by which, namely, man is ordered to a human good. For the habit of this justice can be acquired through human works, but the justice which has glory before God is ordered to the divine good, namely of future glory, which exceeds human capacity, according to that saying in 1 Corinthians 2:9: "Into the heart of man there has not ascended what God has prepared for those who love Him." And therefore the works of man are not proportioned to causing the habit of this justice, but it is necessary that the heart of man first be justified interiorly by God, so that he may perform works proportioned to the divine glory. Then, where he says "For what," etc., he destroys the consequent which was negative, by proving the opposite affirmation, namely that Abraham had glory before God. And this he proves through the authority of Scripture, which the Apostle first sets down; second he expounds it, where he says "But to him," etc. He says therefore first: I say Abraham to be so justified that he has glory before God — for what does Scripture say? Genesis 15:6: Abraham believed God promising him the multiplication of his seed. Ecclesiasticus 2:6: "Believe God, and He will recover you." "And it was reputed to him," namely by God, "unto justice." 1 Maccabees 2:52: "Abraham was found faithful in temptation." And thus it is clear that before God, by whom it was reputed to him unto justice that he believed, he has glory. It must be considered, however, that the justice which God reputes as written, He expressed not in some external work, but in the interior faith of the heart, which God alone beholds. Now since it is said that the act of faith is threefold, namely to believe God, to believe in God, and to believe unto God, he set down this act which is to believe God, which is the proper act of faith, showing its species. For to believe in God shows the order of faith to its end, which is through charity; for to believe in God is, by believing, to go into God, which charity effects. And thus it follows upon the species of faith. But to believe God shows the matter of faith, according as it is a theological virtue, having God for its object. And therefore this act does not yet attain to the species of faith, because if someone should believe that God exists through certain human reasonings and natural signs, he is not yet said to have the faith of which we speak, but only when from this very reason he believes that it was said by God — which is designated by saying "to believe God"; and from this faith is specified, just as any cognitive habit has its species from the reason by which it assents to something. For one having the habit of science is inclined to assent by one reason, namely through demonstration, and one having the habit of opinion by another reason, namely through dialectical syllogism. Then, where he says "But to him who works," etc., he expounds the aforesaid authority as to what it says, "it was reputed to him unto justice," etc. And a twofold exposition of these words is touched upon in the Gloss. The first is according as they are referred to the final reward, concerning which it is shown first how it stands with respect to works, second how it stands with respect to faith, where he says "But to him who does not," etc. He says therefore first, that to him who works — namely, works of justice — the reward, of eternal recompense, concerning which it is said in Isaiah 40:10: "Behold, his reward is with him," is not reputed according to grace only, but according to debt, according to that saying in Matthew 20:13: "Did you not agree with me for a denarius?" But against this is what is said below in 6:23: "the grace of God is eternal life." And below in 8:18: "the sufferings of this time are not worthy to be compared to the glory to come." Thus therefore that recompense is not made according to debt, but according to grace. But it must be said that human works can be considered in two ways. In one way according to the substance of the works, and thus they have nothing condign, such that the reward of eternal glory should be rendered to them. In another way they can be considered according to their principle, namely as they are done from the impulse of God according to the purpose of God predestining; and according to this the aforesaid reward is owed to them according to debt, because, as is said below in 8:14: "those who are led by the Spirit of God, these are the sons of God; but if sons, also heirs." Then, where he says "But to him," etc., he shows how the eternal reward stands with respect to faith, saying: "But to him who does not work" — namely, external works, for instance because he does not have time to work, as is clear in one baptized who dies immediately — "but believes in Him who justifies the ungodly," namely, in God, of whom it is said below, 8:18, "his faith is reputed" — namely alone, without external works — "unto justice," that is, so that by it he may be called just, and may receive the reward of justice, just as if he had done works of justice, according to that saying below, 10:10: "with the heart one believes unto justice," and this "according to the purpose of the grace of God," that is, according as God purposes from His grace to save men. Below, 8:28: "to those who according to His purpose are called saints." Ephesians 1:11: "who works all things according to the counsel of His will." The other exposition is that this be referred to the justification of man. He says therefore "but to him who works," that is, if someone should be justified by works, justice itself would be imputed as a reward not according to grace, but according to debt. Below, 11:6: "But if by grace, now it is not of works; otherwise grace is no longer grace." "But to him who does not work" — namely, so as to be justified by his own works — "but believes in Him who justifies the ungodly" — this faith of his shall be computed unto justice according to the purpose of the grace of God — not indeed so that by faith he merits justice, but because the very act of believing is the first act of justice which God works in him. For from the fact that he believes in God justifying, he subjects himself to His justification, and thus receives its effect. And this exposition is the literal one, and according to the intention of the Apostle, who lays stress on this, that in Genesis 15:6 it is said "it was reputed to him unto justice," which is customarily said when that which is less on someone's part is reputed to him gratis, as if he had done the whole. And therefore the Apostle says that this reputation would have no place, if justice were from works, but it has place only insofar as it is from faith. Then, where he says "as also David," etc., he proves the conditional premised, from the authority of the Psalm. Of which he first sets forth the sense; second he sets down its words, where he says "Blessed are they whose"; third he excludes a false understanding, where he says "the blessedness," etc. He says therefore: as also David says, that is, asserts, the blessedness of man to be that of him, namely, to whom God brings, that is gives, justice, received — that is, freely, without preceding works. Titus 3:5: "For not by works of justice which we have done." Now the blessedness of man is from God, according to that saying in Psalm 39:5: "Blessed is the man whose hope the Lord God is." Thus therefore it is manifest that he has glory before God who is not justified from the works of the law, as has been said. Then, where he says "Blessed are they whose," etc., he sets down the words of David containing the aforesaid statement, and says that they are blessed whose sins are forgiven. And thus it is clear that they did not have prior good works from which they might obtain justice or blessedness. Now sin is threefold, namely original, actual mortal, and actual venial. First therefore, as to original sin, he says: "Blessed are they whose iniquities are forgiven." Here it must be considered that original sin is called iniquity, because it is a lack of original justice, by which, according to equity, the reason of man was subjected to God, the lower powers to reason, and the body to the soul; but through original sin this equity is taken away, because after reason ceased to be subject to God, the lower powers rebel against reason and the body is withdrawn from the obedience of the soul through corruption and death. Whence in Psalm 50:7: "Behold, for I was conceived in iniquities." In both cases, moreover, original sin is signified in the plural. Either because of the many men in whom original sin is multiplied, or rather because it virtually contains in itself, as it were, all sins. This kind of original sin, moreover, is said to be forgiven, because the guilt passes away when grace supervenes, but it remains in act, the tinder or concupiscence remaining, which is not wholly taken away in this life, but is remitted, or mitigated. Second, as to actual mortal sin, he says: "and whose sins are covered." Now sins are said to be covered from the divine sight, insofar as He does not look upon them so as to punish them. Psalm 84:3: "You have covered all their sins." Third, as to venial sin, he says: "Blessed is the man to whom the Lord has not imputed sin," so that by "sin" venial sins are understood, which, although they are light, nevertheless through many of them man is separated and removed far from God. 2 Chronicles 30:18-19: "The good Lord will be merciful to all who seek Him with their whole heart, and it shall not be imputed to them that they are less holy." These three, moreover, can also be distinguished otherwise. For in sin there are three things, of which one is the offense against God, and as to this he says: "Blessed are they whose iniquities are forgiven," according as man is said to forgive an offense done to him. Isaiah 40:2: "Her iniquity is forgiven." Another is the disordered act itself of the fault, which cannot not have been done once it has been perpetrated, but it is covered by the hand of divine mercy, so that it is held as if not done. Third, indeed, is the guilt of punishment, and as to this he says: "Blessed is the man to whom the Lord has not imputed sin," namely, unto punishment. Then, where he says "The blessedness therefore," etc., he excludes a false understanding of the aforesaid authority. For a Jew could understand it thus, that the aforesaid grace of the remission of sins would not come about except to the circumcised. To exclude this, therefore, first the Apostle raises the question, saying: "this blessedness," namely, by which God gives justice without works, "does it remain only in the circumcision," that is, does it have place only in the circumcised, "or also in the uncircumcision," that is, in the Gentiles? It is manifest that it is in both, according to that which he says below, 10:10: "the same Lord is rich unto all," etc. Second, where he says "For we say," he assumes, to show this, the authority of Scripture, as if he should say, I ask this for this reason: "for we say," etc., that "faith was reputed to Abraham unto justice," Genesis 15:6. Third, from this authority he concludes the solution of the aforesaid question, yet under a question, saying: "How then was it reputed?" Namely, the faith of Abraham unto justice, "in circumcision," that is, when he was circumcised, "or in uncircumcision," that is, when he was uncircumcised? And he answers: "not in circumcision, but in uncircumcision." And this is manifest from the sequence of the narrative of Scripture. For in Genesis 15:6 it is read that faith was reputed to Abraham unto justice, but he is read to have received circumcision in Genesis 17:23. If therefore Abraham, while still existing uncircumcised, was justified through faith, it is manifest that the justice of faith, by which sins are freely remitted, is not only in circumcision, but also in uncircumcision, that is, in gentility.”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“For if Abraham were justified by works,.... That Abraham was not, and could not be justified by works, is clear from hence, that if this was his case, he hath whereof to glory; which will be allowed him before men, on account of his pious life and conversation: but not before God; who saw all the iniquity of his heart, and was privy to all his failings and infirmities: besides, glorying before God in a man's own works, is contrary to the scheme and method of God's grace; is excluded by the doctrine of faith; nor is there any place for glorying before God but in Christ, and his righteousness: if therefore Abraham had not that of which he could glory before God, he could not be justified by works in his sight: but does not the Apostle James say that he was justified by works, Jam 2:21? To this it may be replied, that the two apostles, Paul and James, are not speaking of the same thing: Paul speaks of justification before God, James of justification before men; Paul speaks of the justification of the person, James of the justification of a man's cause, as the truth of his faith, or the uprightness of his conduct; Paul speaks of works, as the causes of justification, James of them as the effects and evidences of faith; Paul had to do with the self-righteous, who trusted in their own works for justification, James with Gnostics, who slighted and neglected the performance of them. These things considered, they will be found to agree.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“For if Abraham were justified by works - The Jew proceeds: - I conclude, therefore, that Abraham was justified by works, or by his obedience to this law of circumcision; and, consequently, he has cause for glorying, καυχημα, to exult in something which he has done to entitle him to these blessings. Now, it is evident that he has this glorying, and consequently that he was justified by works. Apostle. But not before God - These seem to be the apostle's words, and contain the beginning of his answer to the arguments of the Jew, as if he had said: - Allowing that Abraham might glory in being called from heathenish darkness into such marvellous light, and exult in the privileges which God had granted to him; yet this glorying was not before God as a reason why those privileges should be granted; the glorying itself being a consequence of these very privileges.”
Source
1849
A.D.
1774–1849
“If Abraham were justified by works, or by his own works, he might have glory, and be commended by men, who judge only according to outward appearances; but not with God: that is, he could not be truly justified, so as to deserve a reward in heaven, without faith and the grace of God. (Witham) — Not with God. Whatever glory or applause such works might procure from men, they would be of no value in the sight of God. (Challoner)”
Source
1871
A.D.
1871
“For if Abraham were justified by works, he hath whereof to glory; but not before God--"If works were the ground of Abraham's justification, he would have matter for boasting; but as it is perfectly certain that he hath none in the sight of God, it follows that Abraham could not have been justified by works." And to this agree the words of Scripture.”
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.