John Gill, on Neh 5:7

And I said unto them,.... The nobles, and rulers, and other rich persons that exacted usury of the poor: we after our ability; speaking of himself in the plural number, which now obtained in the court of Persia; or of Zerubbabel, Ezra, and others, who, according as their worldly circumstances, having been captives, would admit of: have redeemed our brethren the Jews, which were sold unto the Heathen; not that they had given a ransom for them to Cyrus, or any other king of Persia, which would be contrary to the prophecies concerning their redemption, Isa 45:13 but such who had sold themselves to particular persons in Babylon, who, without being redeemed, could not take the advantage of the liberty granted by Cyrus, and his successors; and it may be there were others also in the like circumstances, in other neighbouring nations, that had been redeemed this way. The Jewish canon (i) now is, he that sells himself, and his children, to Gentiles, they do not redeem; but they redeem the children after their father's death; which the commentators (k) explain of the third time that he sells himself: and will you even sell your brethren? their lands and vineyards mortgaged to them, and even their persons: or shall they be sold unto us? must we be obliged to buy them, and to redeem them: then they held their peace, and found nothing to answer; being convinced they had done wrong, by the arguments used, to which they could make no reply. (i) Misn. Gittin, c. 4. sect. 9. (k) Maimon. & Bartenora in ib.