Those who escaped the sword were carried by Nebuchadnezzar into exile in Babylon, and they became servants to him and his sons until the kingdom of Persia came to power.
We have here an account of the destruction of the kingdom of Judah and the city of Jerusalem by the Chaldeans. Abraham, God's friend, was called out of that country, from Ur of the Chaldees, when God took him into covenant and communion with himself; and now his degenerate seed were carried into that country again, to signify that they had forfeited all that kindness...
Commenting on 2 Chronicles 36:11-21
Now in the first year of Cyrus king of Persia,.... These two verses are the same with which the next book, the book of Ezra, begins, where they will be explained; and these two books, the one ending and the other beginning with the same words, is a strong presumption, that one and the same person, Ezra, is the writer of them both; or rather...
And them that had escaped from the sword carried he away to Babylon; where they were servants to him and his sons until the reign of the kingdom of Persia: (k) When Gyrus king of Persia had made the Babylonians subject.