Circumcise, therefore. From this inference it appears wherefore mention was made of this adoption,. viz., that the Jews should more earnestly and solemnly serve God, whom they had known from experience to be so gracious. He requires, then, a reciprocal love; for nothing could be more base than not to testify their gratitude by a pious and righteous life. But, because men are by no means inclined or disposed to obey God, Moses exhorts them to self-renunciation, and to subdue and correct their carnal affections; for to circumcise the heart is equivalent to cleansing it from wicked lusts. Meanwhile, he reproves their former perverseness, when he desires them to be no more stiff-necked; as much as to say, that now at last they should put off that depravity of mind, wherein they had too long hardened themselves. We now perceive the design of Moses. He would have his fellow-Israelites submissive and obedient to God, who, by His great goodness, had furnished them with the motive. But, because hitherto they had repaid His kindnesses with ingratitude, at the same time, he enjoins them to amend their conduct. In the first clause, he alludes to the rite appointed by the Law; for circumcision is, as it were, the solemn consecration, whereby the children of Abraham were initiated unto the worship of God and true piety, and at the same time were separated from heathen nations, to be His holy and peculiar people; and they were to be admitted to this elementary rite in their infancy, that by its visible sign they might learn that the defilements of the flesh and the world were to be renounced. There were also other objects in circumcision, but here reference is only made to newness of life, or repentance (resipiscentia). Wherefore, the conclusion is, that since God had chosen them as His people, and by an external sign had devoted them to the cultivation of holiness, they ought sincerely and really to prove that they differed from heathen nations, and that they were circumcised in spirit, no less than in the flesh. For Paul declares, that they alone are truly Jews who are circumcised "inwardly," as he says, and not those who only have to boast of "the letter" of circumcision. (Romans 2:28, 29.) Wherefore, the Prophets frequently taunt the transgressors of the Law by calling them uncircumcised, although they bore the visible sign in their flesh. In fine, when he desires to exhort them to sanctify themselves to God, he reasons from the nature and use of the sign, whereby they professed themselves to be His chosen people. In the second clause, there is an elegant metaphor, of frequent occurrence, taken from oxen; for, since the oxen which quietly offer their necks to the yoke are easily subdued to obedience, those are said to be "stiff-necked" (durae cervicis) which are fierce and obstinate in their nature.

On "circumcision" see Genesis 17:10. This verse points to the spiritual import of circumcision. Man is by nature "very far gone from original righteousness," and in a state of enmity to God; by circumcision, as the sacrament of admission to the privileges of the chosen people, this opposition must be taken away ere man could enter into covenant with God. It was through the flesh that man first sinned; as it is also in the flesh, its functions, lusts, etc., that man's rebellion against God chiefly manifests itself still. It was fitting therefore that the symbol which should denote the removal of this estrangement from God should be worked in the body. Moses then fitly follows up the command "to circumcise the heart," with the warning "to be no more stiff-necked." His meaning is that they should lay aside that obduracy and perverseness toward God for which he had been reproving them, which had led them into so many transgressions of the covenant and revolts from God, and which was especially the very contrary of that love and fear of God required by the first two of the Ten Commandments. The language associated with circumcision in the Bible distinguishes the use made of this rite in the Jewish religion from that found among certain pagan nations. Circumcision was practiced by some of them as a religious rite, designed (e. g.) to appease the deity of death who was supposed to delight in human suffering; but not by any, the Egyptians probably excepted, at all in the Jewish sense and meaning.
The grounds on which circumcision was imposed as essential by the Law are the same as those on which Baptism is required in the Gospel. The latter in the New Testament is strictly analogous to the former under the Old; compare Colossians 2:11-12.

Circumcise - the foreskin of your heart - A plain proof from God himself that this precept pointed out spiritual things, and that it was not the cutting away a part of the flesh that was the object of the Divine commandment, but the purification of the soul, without which all forms and ceremonies are of no avail. Loving God with all the heart, soul, mind, and strength, the heart being circumcised to enable them to do it, was, from the beginning, the end, design, and fulfillment of the whole law.

(h) Circumcise therefore the foreskin of your heart, and be no more stiffnecked.
(h) Cut off all your evil affections, (Jeremiah 4:4).

Circumcise therefore the foreskin of your heart,.... Content not yourselves with, nor put your confidence in outward circumcision of the flesh, but be concerned for the circumcision of the heart; for removing from that whatever is disagreeable to the Lord, even all carnality, sensuality, hypocrisy, and superfluity of naughtiness, and for having that put there which is well pleasing in his sight; and which though it is the work of God, and he only can do it and has promised it, yet such an exhortation is made to bring men to a sense of their need of it, and of the importance of it, and to show how agreeable it is to the Lord, and so to stir them up to seek unto him for it; see Deuteronomy 30:6.
and be no more stiffnecked; froward, obstinate, and disobedient, as they had been hitherto; Deuteronomy 9:6.

Circumcise therefore the foreskin of your heart--Here he teaches them the true and spiritual meaning of that rite, as was afterwards more strongly urged by Paul (Romans 2:25, Romans 2:29), and should be applied by us to our baptism, which is "not the putting away of the filth of the flesh, but the answer of a good conscience toward God" [1-Peter 3:21].

Above all, therefore, they were to circumcise the foreskin of their hearts, i.e., to lay aside all insensibility of heart to impressions from the love of God (cf. Leviticus 26:41; and on the spiritual signification of circumcision, see Genesis 17:15-21), and not stiffen their necks any more, i.e., not persist in their obstinacy, or obstinate resistance to God (cf. Deuteronomy 9:6, Deuteronomy 9:13). Without circumcision of heart, true fear of God and true love of God are both impossible. As a reason for this admonition, Moses adduces in Deuteronomy 10:17. the nature and acts of God. Jehovah as the absolute God and Lord is mighty and terrible towards all, without respect of person, and at the same time a just Judge and loving Protector of the helpless and oppressed. From this it follows that the true God will not tolerate haughtiness and stiffness of neck either towards Himself or towards other men, but will punish it without reserve. To set forth emphatically the infinite greatness and might of God, Moses describes Jehovah the God of Israel as the "God of gods," i.e., the supreme God, the essence of all that is divine, of all divine power and might (cf. Psalm 136:2), - and as the "Lord of lords," i.e., the supreme, unrestricted Ruler ("the only Potentate," 1-Timothy 6:15), above all powers in heaven and on earth, "a great King above all gods" (Psalm 95:3). Compare Revelation 17:14 and Revelation 19:16, where these predicates are transferred to the exalted Son of God, as the Judge and Conqueror of all dominions and powers that are hostile to God. The predicates which follow describe the unfolding of the omnipotence of God in the government of the world, in which Jehovah manifests Himself as the great, mighty, and terrible God (Psalm 89:8), who does not regard the person (cf. Leviticus 19:15), or accept presents (cf. Deuteronomy 16:19), like a human judge.

Circumcise - Rest not in your bodily circumcision, but seriously set upon that substantial work which is signified thereby: cleanse your hearts from all filthiness and superfluity of naughtiness, fitly compared to the foreskin, which if not cut off, made persons profane, unclean and odious in the sight of God.