Turn thy captivity, i.e. bring back thy captives, as captivity is taken, Psalms 14:7 Ephesians 4:8. Gather thee, i.e. thy children; either spiritually such, as it is explained 1 Thessalonians 11:51,52; or literally such, as it is promised Ro 11 $.
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.