For circumcision indeed profits, etc. He dissipates by anticipation what the Jews might have objected in opposition to him in the defense of their own cause: for since circumcision was a symbol of the Lord's covenant, by which he had chosen Abraham and his seed as his peculiar people, they seemed not to have gloried in vain; but as they neglected what the sign signified, and regarded only the outward form, he gives this answer -- That they had no reason to lay claim to any thing on account of the bare sign. The true character of circumcision was a spiritual promise, which required faith: the Jews neglected both, the promise as well as faith. Then foolish was their confidence. Hence it is, that he omits to state here the main use of circumcision, and proceeds to expose their gross error, as he does in his Epistle to the Galatians. And this ought to be carefully noticed; for if he were explaining the whole character and design of circumcision, it would have been inconsistent in him not to have made mention of grace and free promise: but in both instances he spoke according to what the subject he had in hand required, and therefore he only discussed that part which was controverted. They thought that circumcision was of itself sufficient for the purpose of obtaining righteousness. Hence, speaking according to such an opinion, he gives this reply -- That if this benefit be expected from circumcision, it is on this condition, that he who is circumcised, must serve God wholly and perfectly. Circumcision then requires perfection. The same may be also said of our baptism: when any one confidently relies on the water of baptism alone, and thinks that he is justified, as though he had obtained holiness by that ordinance itself, the end of baptism must be adduced as an objection; which is, that the Lord thereby calls us to holiness of life: the grace and promise, which baptism testifies (testificatur) and seals, (obsignat,) need not in this case to be mentioned; for our business is with those who, being satisfied with the empty shadow of baptism, care not for nor consider what is material (solidum -- substantial) in it. And this very thing you may observe in Paul -- that when he speaks to the faithful of signs, apart from controversy, he connects them with the efficacy and fulfillment of the promises which belong to them; but when he contends with the absurd and unskillful interpreters of signs, he omits all mention of the proper and true character of signs, and directs his whole discourse against their perverted interpretation. Now many, seeing that Paul brings forward circumcision rather than any other part of the law, suppose that he takes away justification only from ceremonies: but the matter is far otherwise; for it always happens, that those who dare to set up their own merits against the righteousness of God, glory more in outward observances than in real goodness; for no one, who is seriously touched and moved by the fear of God, will ever dare to raise up his eyes to heaven, since the more he strives after true righteousness, the clearer he sees how far he is from it. But as to the Pharisees, who were satisfied with imitating holiness by an outward disguise, it is no wonder that they so easily deluded themselves. Hence Paul, after having left the Jews nothing, but this poor subterfuge of being justified by circumcision, does now also take from them even this empty pretense.

For circumcision - John 7:22 note; Acts 7:8 note. This was the special rite by which the relation to the covenant of Abraham was recognised; or by which the right to all the privileges of a member of the Jewish commonwealth was acknowledged. The Jews of course affixed a high importance to the rite.
Verily profiteth - Is truly a benefit; or is an advantage. The meaning is, that their being recognised as members of the Jewish commonwealth, and introduced to the privileges of the Jew, was an advantage; see Romans 3:1-2. The apostle was not disposed to deny that they possessed this advantage, but he tells them why it was a benefit, and how it might fail of conferring any favor.
If thou keep the law - The mere sign can be of no value, The mere fact of being a Jew is not what God requires. It may be a favor to have his Law, but the mere possession of the Law cannot entitle to the favor of God. So it is a privilege to be born in a Christian land; to have had pious parents; to be amidst the ordinances of religion; to be trained in Sundayschools; and to be devoted to God in baptism: for all these are favorable circumstances for salvation. But none of them entitle to the favor of God; and unless they are improved as they should be, they may be only the means of increasing our condemnation; 2-Corinthians 2:16.
Thy circumcision is made uncircumcision - Thy circumcision, or thy being called a Jew, is of no value. It will not distinguish you from those who are not circumcised. You will be treated as a pagan. No external advantages, no name, or rite, or ceremony will save you. God requires the obedience of the heart and of the life. Where there is a disposition to render that, there is an advantage in possessing the external means of grace. Where that is missing, no rite or profession can save. This applies with as much force to those who have been baptized in infancy, and to those who have made a profession of religion in a Christian church, as to the Jew.

For circumcision verily profiteth - It is a blessing to belong to the Church of God and wear the sign of the covenant, provided the terms of the covenant are complied with.
But if thou be a breaker of the law - If thou do not observe the conditions of the covenant, the outward sign is both without meaning and without effect. This was a maxim of the rabbins themselves; for they allowed that an apostate or ungodly Israelite must go to hell, notwithstanding his circumcision.

(9) For circumcision verily profiteth, if thou keep the law: but if thou be a breaker of the law, thy circumcision is made uncircumcision.
(9) He precisely prevents their objection, who set a holiness in circumcision, and the outward observation of the law: so that he shows that the outward circumcision, if it is separated from the inward, does not justify, and also condemns those who are indeed circumcised, of whom it is required that they fulfil that which circumcision signifies, that is to say, cleanness of the heart and the whole life according to the commandment of the law, so that if there is a man uncircumcised according to the flesh, who is circumcised in heart, he is far better and to be more regarded than any Jew that is circumcised according to the flesh only.

For circumcision verily profiteth,.... The plea from circumcision in favour of the Jews, and their acceptance with God, and justification before him, is here, and in the following verses, considered. The apostle allows that circumcision was profitable; which must be understood whilst it was in force, before the abrogation of it, for since, it is not profitable but pernicious; and then it was only profitable, in case the law was kept:
if thou keepest the law; that is, perfectly; for circumcision obliged persons to keep the whole law. Now the circumcised Jews did not keep it in such sense; wherefore circumcision was of no use to them, but, on the contrary, was an handwriting against them.
But if thou be a breaker of the law, thy circumcision is made uncircumcision; that is, it is not accounted circumcision; it is of no avail; such a man was all one as an uncircumcised Gentile, and appeared to be uncircumcised in a spiritual sense: the apostle perhaps alludes to a practice among some of the Jews, to bring on and draw over the foreskin, after they had been circumcised; See Gill on 1-Corinthians 7:18.

No forms, ordinances, or notions can profit, without regenerating grace, which will always lead to seeking an interest in the righteousness of God by faith. For he is no more a Christian now, than he was really a Jew of old, who is only one outwardly: neither is that baptism, which is outward in the flesh: but he is the real Christian, who is inwardly a true believer, with an obedient faith. And the true baptism is that of the heart, by the washing of regeneration and the renewal of the Holy Ghost; bringing a spiritual frame of mind, and a willing following of truth in its holy ways. Let us pray that we may be made real Christians, not outwardly, but inwardly; in the heart and spirit, not in the letter; baptized, not with water only, but with the Holy Ghost; and let our praise be, not of men, but of God.

For circumcision--that is, One's being within the covenant of which circumcision was the outward sign and seal.
verily profiteth, if thou keep the law--if the inward reality correspond to the outward sign.
but if, &c.--that is, "Otherwise, thou art no better than the uncircumcised heathen."

For circumcision verily profiteth. The Jew was wont to fall back on his circumcision, as some still do on some outward ordinance. His answer to Paul is, Are we not the circumcised? Are not the circumcised the people of the covenant? He replied, "I admit that circumcision availeth, if one keeps law. The outward observance profits if one be a law-doer; that is, complies with its moral commandments. But if he fails to do this, his circumcision is as worthless as though he was uncircumcised." The effect of habitual transgression is to annul the covenant.
The converse of this is also true. If the Jewish law-breaker can annul his circumcision thus, then if the uncircumcision (the Gentiles) keep the righteousness of the law, his uncircumcised state will not be counted against him. He supposes the possible case of a Gentile who might render such an obedience to the moral precepts of the law as a pious Jews could render, and argues that his uncircumcision would not make his obedience less acceptable. Circumcision is not, then, the thing that the Gentile needs, but righteousness. The disobedient Jew virtually becomes a Gentile, and the obedient Gentile virtually becomes a Jew.
Uncircumcision which is by nature. The Gentiles, who are of uncircumcised races. If such an one keeps the essential principles of the law, his obedience is a rebuke to the Jewish transgressor who has covenanted to keep the law.
For he is not a Jew. He is not a Jew, in the religious sense of one of God's chosen people, who is one outwardly alone.
Neither is that circumcision, the true circumcision, that which makes one a member of God's covenanted church, "which is outward in the flesh."
But he is a Jew, such a Jew as just described, who is one inwardly, whose heart is given to God; and circumcision is that of the heart. Circumcision of the heart is a figurative expression for inward purity, as old as the book of Deuteronomy. See Deuteronomy 10:16, and Deuteronomy 30:6; also Jeremiah 9:26. This circumcision is not an outward mark in the flesh of the body, but is in the spirit. The spirit of man is under the influence of the Spirit.
Not in the letter. Not literal.
Whose praise is not of men. The Jew, as we have seen, made his boasts, and praised his privileges, but though the true Jew, such as Paul describes, shall be ill-spoken of by men, but shall have praise of God. The whole section shows that religious privileges, resulting from birth, the revelation of God's will, ritual observances and knowledge, increase the guilt of those whose morality does not correspond. The Jews, especially the Pharisees, were very eager for the praise of men, but the true Jew, the real child of Abraham's by faith, will have what is infinitely better, the praise of God.

Circumcision indeed profiteth - He does not say, justifies. How far it profited is shown in the third and fourth chapters. Thy circumcision is become uncircumcision - is so already in effect. Thou wilt have no more benefit by it than if thou hadst never received it. The very same observation holds with regard to baptism.