Circumcise thine heart - Compare Deuteronomy 10:16 note; Jeremiah 32:39; Ezra 11:19.

God will circumcise thine heart - This promise remains yet to be fulfilled. Their heart, as a people, has never yet been circumcised; nor have the various promises in this chapter been ever yet fulfilled. There remaineth, therefore, a rest for this people of God. Now, as the law, properly speaking, made no provision for the circumcision of the heart, which implies the remission of sins, and purification of the soul from all unrighteousness; and as circumcision itself was only a sign of spiritual good, consequently the promise here refers to the days of the Messiah, and to this all the prophets and all the apostles give witness: "for circumcision is that of the heart, in the spirit, and not in the letter," Romans 2:29; and the genuine followers of God are circumcised with the circumcision made without hands - by the circumcision of Christ," Colossians 2:11, Colossians 2:12. Hence we see these promises cannot be fulfilled to the Jews but in their embracing the Gospel of Christ. To look, therefore, for their restoration is idle and nugatory, while their obstinacy and unbelief remain.

And the Lord thy God will circumcise thine heart, and the heart of thy seed,.... No mention is made of circumcision of the flesh, which will now be out of use with the Jews; they being fully convinced of the abrogation of the ceremonial law by the Messiah, whom they will now receive. It is spiritual circumcision only that is here spoken of, with which the Jews will be circumcised, when they shall be pricked and cut to the heart, and be thoroughly convinced of sin; when the iniquity of their hearts will be laid open to them, and they put to pain, and filled with shame and loathing for it; when the hardness of their hearts will be removed, and the foolishness of them will be exposed and taken away, and they will be made willing to part with their sins, and with their own righteousness; when the graces of the Spirit will be implanted in them, and the blood of Christ applied to them for pardon and cleansing. This is the circumcision made without hands, which is not of men, but of God; what he calls for, and exhorts unto, as being necessary, Deuteronomy 10:16; he here promises to do; and deed none but himself can do it; for he only can come at the hearts of men, to take anything out of them, or put anything into them; it is he that opens the heart, softens, quickens, enlightens, and purifies it: Baal Hatturim says this respects the times of the Messiah:

to love the Lord thy God with all thine heart, and with all thy soul; which, though the duty of every man, is performed by none but those that have the grace of God; there is no love to God in the heart before this inward and spiritual circumcision of it: it is a fruit of the Spirit in conversion when the affections are taken off of other things, and set on Christ; when a man sees his sin and his Saviour, and the one is odious, and the other precious; when the blessings of grace are applied, and the love of God is shed abroad in the heart, which cause love to God and Christ again:

that thou mayest live; spiritually and eternally; for there is no spiritual life in the soul till the heart is circumcised, or, in other words, regenerated and renewed; then it is quickened; then a man lives a life of faith on Christ, of holiness from him, communion with him, and has both an open right unto, and meetness for, eternal life.

The Lord will then circumcise their heart, and the heart of their children (see Deuteronomy 10:16), so that they will love Him with all their heart. When Israel should turn with true humility to the Lord, He would be found of them, - would lead them to true repentance, and sanctify them through the power of His grace, - would take away the stony heart out of their flesh, and give them a heart of flesh, a new heart and a new spirit, - so that they should truly know Him and keep His commandments (vid., Ezekiel 11:19; Ezekiel 36:26; Jeremiah 31:33. and Deuteronomy 32:39.). "Because of thy life," i.e., that thou mayest live, sc., attain to true life. The fulfilment of this promise does not take place all at once. It commenced with small beginnings at the deliverance from the Babylonian exile, and in a still higher degree at the appearance of Christ in the case of all the Israelites who received Him as their Saviour. Since then it has been carried on through all ages in the conversion of individual children of Abraham to Christ; and it will be realized in the future in a still more glorious manner in the nation at large (Romans 11:25.). The words of Moses do not relate to any particular age, but comprehend all times. For Israel has never been hardened and rejected in all its members, although the mass of the nation lives under the curse even to the present day.

And the LORD thy God will {e} circumcise thine heart, and the heart of thy seed, to love the LORD thy God with all thine heart, and with all thy soul, that thou mayest live.

(e) God will purge all your wicked affections, a thing that is not in your own power to do.

30:6 And the Lord - Or, For the Lord will circumcise thine heart, will by his word and spirit change and purge thy heart from all thine idolatry and wickedness, and incline thy heart to love him. God will first convert and sanctify them, the fruit whereof shall be, that they shall return and obey God's commandments, Deu 30:8, and then shall prosper in all things, Deu 30:9. This promise principally respects the times of the gospel, and the grace which was to be then imparted to all Israel by Christ.

30:1-10 In this chapter is a plain intimation of the mercy God has in store for Israel in the latter days. This passage refers to the prophetic warnings of the last two chapters, which have been mainly fulfilled in the destruction of Jerusalem by the Romans, and in their dispersion to the present day; and there can be no doubt that the prophetic promise contained in these verses yet remain to come to pass. The Jewish nation shall in some future period, perhaps not very distant, be converted to the faith of Christ; and, many think, again settled in the land of Canaan. The language here used is in a great measure absolute promises; not merely a conditional engagement, but declaring an event assuredly to take place. For the Lord himself here engages to circumcise their hearts; and when regenerating grace has removed corrupt nature, and Divine love has supplanted the love of sin, they certainly will reflect, repent, return to God, and obey him; and he will rejoice in doing them good. The change that will be wrought upon them will not be only outward, or consisting in mere opinions; it will reach to their souls. It will produce in them an utter hatred of all sin, and a fervent love to God, as their reconciled God in Christ Jesus; they will love him with all their hearts, and with all their soul. They are very far from this state of mind at present, but so were the murderers of the Lord Jesus, on the day of Pentecost; who yet in one hour were converted unto God. So shall it be in the day of God's power; a nation shall be born in a day; the Lord will hasten it in his time. As a conditional promise this passage belongs to all persons and all people, not to Israel only; it assures us that the greatest sinners, if they repent and are converted, shall have their sins pardoned, and be restored to God's favour.