The interpretation timeline
Romans 6:20 Douay-Rheims

For when you were the servants of sin, you were free men to justice.

A.D. 407 – 1871 6 witnesses

Patristic

before A.D. 750
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“Now what he says is somewhat of this kind, When ye lived in wickedness, and impiety, and the worst of evils, the state of compliance ye lived in was such that ye did absolutely no good thing at all. For this is, "ye were free from righteousness." That is ye were not subject to it, but estranged from it wholly. For ye did not even so much as divide the manner of servitude between righteousness and sin, but gave yourselves wholly up to wickedness. Now, therefore, since ye have come over to righteousness, give yourselves wholly up to virtue, doing nothing at all of vice, that the measure you give may be at least equal. And yet it is not the mastership only that is so different, but in the servitude itself there is a vast difference. And this too he unfolds with great perspicuity, and shows what conditions they served upon then, and what now. And as yet he says nothing of the harm accruing from the thing, but hitherto speaks of the shame.”
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
“For when ye were the servants of sin,.... This is an argument used, or a reason given, why regenerate persons should be diligent in the service of righteousness; because when they were employed in the drudgery of sin, they were free from righteousness; they had no righteousness, nor were they desirous of any; yea, averse to it, threw off the yoke of the law of righteousness, and lived in a very unrighteous manner: hence may be observed what is the free will of man in an unregenerate state; not free to, but "from" righteousness; free enough to evil, but from all that is good; and also what obligation lies upon believers, who are delivered from the bondage of corruption, and the servitude of sin, to a life and service of righteousness; inasmuch as they were before free from it, and unconcerned about it, but are now made by the grace of God free to it, they ought therefore cheerfully to pursue it, and neglect no opportunity of performing it.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“Ye were free from righteousness - These two servitudes are incompatible; if we cannot serve God and Mammon, surely we cannot serve Christ and Satan. We must be either sinners or saints; God's servants or the devil's slaves. It cannot be as a good mistaken man has endeavored to sing: - "To good and evil equal bent, I'm both a devil and a saint." I know not whether it be possible to paint the utter prevalence of sin in stronger colors than the apostle does here, by saying they were Free from righteousness. It seems tantamount to that expression in Genesis, Gen 6:5, where, speaking of the total degeneracy of the human race, the writer says, Every imagination of the thoughts of his heart was only evil continually. They were all corrupt; they were altogether abominable: there was none that did good; no, not one.”
Source
1849
A.D.
1774–1849
“You were free from justice; that is, says St. Chrysostom, you lived as no ways subject to justice, nor obedient to the law and precepts of God: an unhappy freedom, a miserable liberty, worse than the greatest slavery, the end of which is death, eternal death: of which sins with great reason you are now ashamed, when you are become the servants of God, and obedient to him, for which you will receive the fruit and reward of everlasting life in heaven. (Witham)”
Source
1871
A.D.
1871
“For when ye were the servants--"were servants" of Sin, ye were free from--rather, "in respect of" Righteousness--Difficulties have been made about this clause where none exist. The import of it seems clearly to be this:--"Since no servant can serve two masters, much less where their interests come into deadly collision, and each demands the whole man, so, while ye were in the service of Sin ye were in no proper sense the servants of Righteousness, and never did it one act of real service: whatever might be your conviction of the claims of Righteousness, your real services were all and always given to Sin: Thus had ye full proof of the nature and advantages of Sin's service." The searching question with which this is followed up, shows that this is the meaning.”
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.