Deuteronomy 23:19-20 - Interest On Loans
19 Do not take interest from an Israelite on anything, money or food or any other goods, which you let him have 20 From men of other nations you may take interest, but not from an Israelite: so that the blessing of the Lord your God may be on everything to which you put your hand, in the land which you are about to take as your heritage.