The interpretation timeline
Romans 6:21 Douay-Rheims

What fruit therefore had you then in those things, of which you are now ashamed? For the end of them is death.

A.D. 407 – 1871 5 witnesses

Patristic

before A.D. 750
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“So great was the slavery, that even the recollection of it now makes you ashamed; but if the recollection makes one ashamed, the reality would much more. And so you gained now in two ways, in having been freed from the shame; and also in having come to know the condition you were in; just as then ye were injured in two ways, in doing things deserving shame, and in not even knowing to be ashamed. And this is worse than the former. Yet still ye kept in a state of servitude. Having then proved most abundantly the harm of what took place then from the shame of it, he comes to the thing in question. Now what is this thing? "For the end of those things is death." Since then shame seems to be no such serious evil, he comes to what is very fearful, I mean death; though in good truth what he had before mentioned were enough. For consider how exceeding great the mischief must be, inasmuch as, even when freed from the vengeance due to it, they could not get free of the shame. What wages then, he says, do you expect from the reality, when from the bare recollection, and that too when you are freed from the vengeance, you hide your face and blush, though under such grace as you are! But God's side is far otherwise.”
Source

Scholastic

c. 1100 – 1500
1273
A.D.
Thomas Aquinas Catholic
1225–1274
“After the Apostle showed, by an argument taken from the divine benefit, that we ought not to remain in sin but should serve God, here he shows the same thing by an argument taken from the custom of our former life. And concerning this he does three things. First he sets forth the condition of the teaching he supposes, which he adds; second he sets forth the expression of the teaching, at "for as you have yielded," etc.; third he assigns the reason for the teaching, at "for when you were servants." He says therefore first: I have warned that you yield yourselves to God; I still say to you a certain human thing, that is, something fitting to human weakness. For thus "man" is sometimes taken in Scripture, namely insofar as it signifies the condition of human weakness; Wisdom 9:5: "a weak man, and of short time, and too little for the understanding of judgment and laws." 1 Corinthians 3:3: "since there is among you zeal and contention, are you not carnal, and walk according to man?" He assigns the cause, adding "because of the weakness" of your flesh; for to the perfect more perfect precepts are to be handed down. 1 Corinthians 2:6: "we speak wisdom among the perfect." Hebrews 5:14: "solid food is for the perfect." To the weaker, lighter precepts are to be given. 1 Corinthians 3:1-2: "as to little ones in Christ, I gave you milk to drink, not meat." Hebrews 5:12: "you have become such as have need of milk." But this weakness comes not from the spirit but from the flesh, because "the corruptible body weighs down the soul," as is said in Wisdom 9:15. And therefore he adds "of your flesh." Matthew 26:41: "the spirit indeed is willing, but the flesh is weak." Then, when he says "for as you have yielded," etc., he sets forth the teaching which he says is human, in which he teaches that the body is to be yielded equally to serve justice, according as we have yielded it to serve sin. And this is what he means when he says "for as you have yielded your members to serve," namely through the carrying out of evil work, uncleanness and iniquity conceived in the heart: so that uncleanness refers to carnal sins, Ephesians 5:3: "let all fornication, or uncleanness... not so much as be named among you," etc.; while iniquity refers to spiritual sins, and especially those by which the neighbor is harmed. Psalm: "he has plotted iniquity on his bed." When these are conceived in the heart, the members serve unto iniquity, namely, so as to carry it out in deed. And here he sets down "iniquity" for both uncleanness and iniquity, 1 John 3:4, according as every sin is iniquity. And this insofar as it is discordant from the equity of the divine law. So now, namely having been freed from sin, yield your members, namely through the carrying out of good works, to serve justice, as set before us in the divine law: and this unto sanctification, that is, unto the carrying out and increase of holiness. Apocalypse, last chapter: "let him who is holy be sanctified still." He says this is human, because according to right judgment it would be required that man serve justice much more than he had before served sin. Baruch 4:28: "as it was your mind to go astray from God ten times as much, so returning again you shall seek him." He accordingly assigns the reason for this teaching, saying "for when you were servants," etc. And concerning this he does two things. First he sets forth the reason for what was said above; second he proves what he had supposed, at "the wages of sin is death," etc. He shows the reason for what was said before by preferring the state of grace to the state of fault. For if more goods come to us from justice than from fault, we ought the more to press on to serve justice, than we had striven to serve sin. First therefore he sets forth the condition of the state of sin; second, the condition of the state of justice, at "but now being made free," etc. Concerning the first he does three things. First he sets forth the condition of sin; second, the effect of sin, at "what fruit therefore," etc. Third, the end, at "for the end of those things," etc. Concerning the first, it must be considered that man is naturally of free will, on account of reason and will, which cannot be compelled, yet can be inclined by certain things. Always therefore man, as regards the judgment of reason, remains free from coercion, yet is not free from inclination. For sometimes free will is inclined to good through the habit of grace or of justice: and then it has the servitude of justice and is free from sin. But sometimes the will is inclined to evil through the habit of sin: and then it has the servitude of sin and the freedom of justice. The servitude of sin indeed is that by which it is drawn to consent to sin, against the judgment of reason. John 8:34: "he who commits sin, is the servant of sin." And as to this he says: "for when you were the servants of sin." But freedom from justice is this, that man without the rein of justice hurls himself headlong into sin. And as to this he says "you were free from justice," which especially happens to those who sin from a fixed resolve. For those who sin from weakness or passion are held back by some rein of justice, so that they do not appear entirely free from justice. Jeremiah 2:20: "of old time you have broken the yoke, you have burst the bands, and said, I will not serve." Job 11:12: "a vain man is lifted up into pride, and thinketh himself born free like a wild ass's colt." It must be known, however, that this state has true servitude, but not true freedom, only apparent freedom. For since man is what he is according to reason, then a man is truly a servant when he is led away by something foreign from that which belongs to reason. But that someone is not restrained by the rein of reason from following concupiscence is freedom only according to the opinion of him who thinks the highest good is to follow the things desired. Then when he says "what fruit therefore," etc., he shows the effect of sin. And he indeed excludes one effect, namely a fruitful effect, when he says "what fruit therefore," namely when you sinned in those, namely, sins. For the works of sin are fruitless, because they do not help man to attain to beatitude. Isaiah 59:6: "their works are unprofitable works." Micah 2:1: "woe to you that devise that which is unprofitable, and work evil in your beds." He then adduces a shameful effect, saying "in which," namely, sins, that is, of which now, namely in the state of repentance, you are ashamed, because of their baseness. Jeremiah 31:19: "after you showed me, I struck my thigh with confusion, and I blushed." Isaiah 1:29: "you shall be ashamed of the gardens," namely, of pleasure, "which you had chosen." Then when he says "for the end," etc., he sets forth the end of sin, saying "for the end of those things," namely of sins, "is death." This, indeed, even if it is not the end intended by the one committing the sin — because in sinning he does not intend to incur death — is nevertheless the end of the sins themselves, because of themselves they are apt to bring on temporal death, since when the soul separates God from itself, it is fitting that its body be separated from it; and eternal death, because when someone wishes to be separated from God for a time, on account of the concupiscence of sin, it is fitting that he be separated from God eternally, which is eternal death. Above, 1:32: "they that do such things, are worthy of death." Then when he says "but now," etc., he shows the character of the state of justice. And first he sets forth the condition of the state of justice; second, the effect, at "you have your fruit," etc.; third he sets forth the end, at "but the end," etc. Concerning the first, it must be considered that just as when someone is inclined to evil by sin, he is free from justice, so when someone is inclined to good by the habit of justice and grace, he is free from sin, namely so that he is not overcome by it even to the point of consent. Hence he says "but now," namely in the state of justice, "made free from sin." John 8:36: "if the son shall make you free, you shall be free indeed." Likewise, conversely, just as in the state of sin someone is a servant of sin, whom he obeys, so in the state of justice someone is a servant of God, obeying voluntarily, according to Psalm 99:2: "serve the Lord with gladness." And this is what he adds, "but become servants to God." Psalm 115:16: "O Lord, for I am your servant," etc. This, however, is true freedom, and the best servitude; because through justice man is inclined to that which is fitting to him, which is proper to man, and is turned away from that which is fitting to concupiscence, which is most bestial. Then when he says "you have your fruit," etc., he sets forth the effect of justice, saying "you have your fruit unto sanctification," that is, sanctification itself, that is, the carrying out of holiness through good works, is your fruit, insofar as this delights you spiritually and holily. Ecclesiasticus 24:23: "my flowers are the fruit of honor and riches," etc. Galatians 5:22: "the fruit of the Spirit is joy, peace," etc. Accordingly he sets forth the end, saying "but the end you have is life everlasting." This indeed is the end of the just themselves, who do all things for the sake of having eternal life. Matthew 6:33: "seek first the kingdom of God," etc. And also of their works themselves, which, since they are done out of obedience to God and in imitation of God, merit eternal life. John 10:27-28: "my sheep hear my voice, and follow me, and I give them life everlasting." Then when he says "for the wages of sin," etc., he makes clear what he had said about the ends of evils and goods. And first as to evils. He says: it has been said that the end of sins is death, "for the wages of sin is death." Now "wages" are called the pay of soldiers, from the stips to be weighed out, that is, weighed: because the money to be distributed to soldiers used to be weighed. Since therefore sinners serve as soldiers to sin, yielding their members as weapons to sin, as was said above, death is said to be the wages of sin, that is, the retribution which it renders to those serving it. And from this it is clear that death is the end of sins, not one which those who sin seek, but one which is rendered to them. Psalm 10:6: "fire and brimstone and the storm of winds, shall be the portion of their cup." But as to goods, he says "the grace of God is life everlasting." For since he had said that just men have eternal life, which it is certain cannot be had except through grace: therefore this very fact that we work good things, and that our work is worthy of eternal life, is from the grace of God. Hence also in Psalm 83:12 it is said: "the Lord will give grace and glory." Thus therefore our works, if they are considered in their own nature and according as they proceed from the free will of man, do not merit eternal life condignly, but only according as they proceed from the grace of the Holy Spirit. Hence it is said, John 4:14: "it shall become in him a fountain of water springing up into life everlasting." And this comes about "in Christ Jesus our Lord," that is, through Christ, or insofar as we are in him through faith and charity. John 6:40: "everyone who sees the Son, and believes in him, has life everlasting."”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“What fruit had ye then in those things?.... That is, what profit, pleasure, satisfaction, or comfort, had ye in the commission of sin? Sin yields no real profit to the servants of it. If a man, by sinful practices, could amass together the riches of the Indies, or gain the whole world, yet if his soul is lost thereby, what advantage would it be to him? he would be infinitely the loser by it; nor would all his wealth and riches profit him in the day of God's wrath and righteous judgment: nor is there any true pleasure in sin; persons may imagine within themselves they enjoy a real pleasure whilst they are serving divers lusts; but this is but imaginary, it is not real; and this imaginary pleasure is but for a season; it issues in bitterness and death: nor is there any satisfaction in it; when men have endeavoured to gratify their carnal lusts and sensual appetites in every way that can be devised, they still remain as they were; nor can they reflect with real satisfaction, and without some slinging remorse, upon the methods they have pursued to gain it: nor is there any true honour in sin, nothing but what is scandalous and disgraceful to human nature; shame, sooner or later, is the fruit of sin: whereof ye are now ashamed; some men may be indeed for the present so hardened as not to blush and be ashamed at the commission of the vilest sins; such are they who have no sense of sin, have no fear of God, or regard to men; and so sin openly, and without any guise, glory in it, and make their boast of it: but when persons are wrought upon by the Spirit of God, they are ashamed of sin; which might be exemplified in the case of Adam and Eve, of Ephraim, of the prodigal son, and of the poor publican; the reason is, because light is struck into their hearts; and this makes manifest the odious and detestable nature of sin; sin is hereby seen in its own proper colours, as exceeding sinful, loathsome, and abominable: besides, the grace and goodness of God are discovered in the forgiveness of it; and the glory of God's purity and holiness, and the beauty and loveliness of Christ, are discerned by such persons; all which have a tendency to make them ashamed of sin, out of love with it, and to abhor it: and a good thing it is to be brought to be ashamed of sin here; for such who are not ashamed of it here, shall be brought to everlasting shame and confusion hereafter. Nay, this is not all; not only shame will be the fruit of sin, but it will also issue in death: for the, end of those things is death: the profit, the reward, and wages of them is death: sin not only brings a spiritual or moral death on persons, on all the powers and faculties of their souls, and is followed with a corporeal death; but if grace prevent not, it will end in an eternal one; for however right and good the ways of sin may seem to the carnal mind, "the end thereof are the ways of death" (#Pr 14:12 16:25).”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“What fruit had ye then in those things - God designs that every man shall reap benefit by his service. What benefit have ye derived from the service of sin? Whereof ye are now ashamed? - Ye blush to remember your former life. It was scandalous to yourselves, injurious to others, and highly provoking to God. The end of those things is death - Whatever sin may promise of pleasure or advantage, the end to which it necessarily tends is the destruction of body and soul.”
Source
1871
A.D.
1871
“What fruit had ye then in those things whereof ye are now ashamed? for the end of those things is death--What permanent advantage, and what abiding satisfaction, have those things yielded? The apostle answers his own question:--"Abiding satisfaction, did I ask? They have left only a sense of 'shame.' Permanent advantage? 'The end of them is death.'" By saying they were "now ashamed," he makes it plain that he is not referring to that disgust at themselves, and remorse of conscience by which those who are the most helplessly "sold under sin" are often stung to the quick; but that ingenuous feeling of self-reproach, which pierces and weighs down the children of God, as they think of the dishonor which their past life did to His name, the ingratitude it displayed, the violence it did to their own conscience, its deadening and degrading effects, and the death--"the second death"--to which it was dragging them down, when mere Grace arrested them. (On the sense of "death" here, see on Rom 5:12-21, Note 3, and Rom 6:16 : see also Rev 21:8 --The change proposed in the pointing of this verse: "What fruit had ye then? things whereof ye are now ashamed" [LUTHER, THOLUCK, DE WETTE, PHILIPPI, ALFORD, &c.], seems unnatural and uncalled for. The ordinary pointing has at least powerful support [CHRYSOSTOM, CALVIN, BEZA, GROTIUS, BENGEL, STUART, FRITZSCHE]).”
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.