Concise Bible Dictionary:
On the return of the Jews from exile, there were many poor, and in order to get food they borrowed money on their land, which gave the lender a claim on the property, even as mortgages are now negotiated. The money was lent by rich Jews, and Nehemiah was very angry at their exacting usury and strongly condemned them. They ought to have given sustenance to their poorer brethren (Neh. 5:3).