The Lord will turn thy captivity That is, will bring back thy captives, as the following words imply. Indeed, captivity is often put for captives, Psalms 14:7; and Psalms 68:18; Judges 5:12. This was fulfilled in part when they returned from Babylon, and will be more completely fulfilled when they shall turn from ungodliness, and believe with their heart unto righteousness in Jesus of Nazareth, as the Son of God, and true Messiah; but surely not before; for as they were cast out of their own land for rejecting him, it is not to be supposed that they will be restored to it till they receive him. Nor is there any intimation in any part of Scripture that they shall. Their repentance and reformation must precede their obtaining this mercy: see Romans 11:26. Thus Moses here, When thou shalt return unto the Lord with all thy heart and all thy soul, then the Lord will have compassion upon thee, and gather thee from all the nations, &c. Till then any efforts that may be used to re-establish them in Canaan will prove ineffectual.
Related Commentaries of Deuteronomy 30:3
Deuteronomy 30:3
3 That then the LORD thy God will turn thy captivity, and have compassion upon thee, and will return and gather thee from all the nations, whither the LORD thy God hath scattered thee.