The interpretation timeline
Romans 6:19 Douay-Rheims

I speak an human thing, because of the infirmity of your flesh. For as you have yielded your members to serve uncleanness and iniquity, unto iniquity; so now yield your members to serve justice, unto sanctification.

A.D. 407 – 1871 6 witnesses

Patristic

before A.D. 750
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“Since he had required great strictness of life, charging us to be dead to the world, and to have died unto wickedness, and to abide with no notion towards the workings of sin, and seemed to be saying something great and burdensome, and too much for human nature; through a desire to show that he is not making any exorbitant demand, nor even as much as might be expected of one who enjoyed so great a gift, but one quite moderate and light, he proves it from contraries, and says, "I speak after the manner of men," as much as to say, Going by human reasonings; by such as one usually meets with. For he signifies either this, or the moderateness of it, by the term applied, "after the manner of men." For elsewhere he uses the same word. "There hath no temptation taken you but such as is common to man," that is, moderate and small. "For as ye have yielded your members servants to uncleanness and to iniquity unto iniquity; even so now yield your members servants to righteousness unto holiness." And truly the masters are very different ones, but still it is an equal amount of servitude that I ask. For men ought to give a much larger one, and so much the larger as this is a greater and better mastership than the other. Nevertheless I make no greater demand "because of the infirmity," and that, he does not say of your free will or readiness of spirit, but "of your flesh," so making what he says the less severe. And yet on one side there is uncleanness, on the other holiness: on the one iniquity, and on the other righteousness. And who is so wretched, he says, and in such straits as not to spend as much earnestness upon the service of Christ, as upon that of sin and the devil? Hear then what follows, and you will see clearly that we do not even spend this little. For when (stated in this naked way) it does not seem credible or easy to admit, and nobody would endure to hear that he does not serve Christ so much as he did serve the devil, he proves it by what follows, and renders it credible by bringing that slavery before us, and saying how they did serve him.”
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
“I speak after the manner of men,.... This refers either to what the apostle had said already concerning service and liberty, things which were known among men, and easy to be understood; or to the following exhortation: what he was about to say, he delivered in a manner suited to their understandings, and was "that which was human"; not angelic, or what required the power, purity, and perfection of angels; or what was unreasonable or impossible, but what was their reasonable service, as men; and might be done through the grace of God, in the strength of Christ, and by the assistance of the Spirit: and though he might have insisted upon it with good reason, that they ought to be more diligent and industrious in the service of God than they had been in the service of sin; yet because of the infirmity of their flesh, considering that they had flesh, or corrupt nature, and were attended with weakness in knowledge, faith, and obedience; he only pressed this upon them, that in like manner as they had been servants to sin, they would be servants to righteousness: for as ye have yielded your members servants to uncleanness, and to iniquity unto iniquity; what they yielded to the service of sin were their "members"; by which, as before, may be meant, either the powers and faculties of their souls, or the parts and members of their bodies, or both; and particularly the latter, as the eyes and ears, the tongue, the mouth, the hands, and feet, which are all employed by a natural man in the drudgery of sin: these are yielded to sin under the form and character of "servants"; and as such are governed, directed, and ordered to fulfil this and the other lust, which is done willingly and readily: these members are "yielded", presented, and given up cheerfully to this slavery; which is both scandalous and unrighteous: it is "to uncleanness"; which designs all sorts of pollution and filthiness, both of flesh and spirit: "and to iniquity"; everything that is contrary to the law, all unrighteousness and ungodliness; and it is added, "unto iniquity"; which may design all sorts of sin, a progress in it, adding continually to it; which shows them to have been thorough hearty servants of sin. Now what the apostle exhorts to, and requires of them, is, that even so now they would yield their members servants to righteousness unto holiness; that is, let the same members that have been employed in the service of sin, be made use of in the service of righteousness: let your eyes be employed in looking and diligently searching into the Scriptures of truth; your ears in hearing the Gospel preached; your lips, mouth, and tongue, in expressing the praises of God, for what he has done for you; your hands in distributing to the interest of religion, and the necessities of the saints; and your feet in hastening to attend on public worship, and observe the testimonies of the Lord: let them be employed under the same form and character as servants, waiting upon the Lord, ready to fulfil his will; and in the same manner, freely, willingly, and cheerfully, and that constantly and universally, in all acts of righteousness and holiness.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“I speak after the manner of men - This phrase is often used by the Greek writers to signify what was easy to be comprehended; what was ad captum vulgi, level with common understandings, delivered in a popular style; what was different from the high flights of the poets, and the studied sublime obscurity of the philosophers. Because of the infirmity of your flesh - As if he had said: I make use of metaphors and figures connected with well-known natural things; with your trades and situation in life; because of your inexperience in heavenly things, of which ye are only just beginning to know the nature and the names. Servants to uncleanness, etc. - These different expressions show how deeply immersed in and enslaved by sin these Gentiles were before their conversion to Christianity. Several of the particulars are given in the first chapter of this epistle.”
Source
1849
A.D.
1774–1849
“I speak a human thing, [2] or I am proposing to you what is according to human strength and ability assisted by the grace of God, with a due regard to the weakness and infirmity of your flesh. The sense, according to St. Chrysostom is this, that the apostle having told them they must be dead to sin, lead a new life, &c. he now encourages them to it, by telling them, that what is required of them is not above their human strength, as it is assisted by those graces which God offers them, and which they have received. Where we may observe that these words, I speak a human thing, are not the same, nor to be taken in the same sense, as chap. iii. 6. when he said, I speak after a human way, or I speak like men. (Witham) — What I ask of you, Christian Romans, is, that you so earnestly labour for your sanctification as to improve daily in virtue, as formerly you plunged every day deeper and deeper into vice. (Menochius)”
Source
1871
A.D.
1871
“I speak after the manner of men--descending, for illustration, to the level of common affairs. because of the infirmity of your flesh--the weakness of your spiritual apprehension. for as ye have yielded--"as ye yielded," the thing being viewed as now past. your members servants to Uncleanness and to Iniquity unto--the practice of iniquity; even so now yield your members servants to Righteousness unto holiness--rather, "unto (the attainment of) sanctification," as the same word is rendered in Th2 2:13; Co1 1:30; Pe1 1:2 : --that is, "Looking back upon the heartiness with which ye served Sin, and the lengths ye went to be stimulated now to like zeal and like exuberance in the service of a better Master."”
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.