Deuteronomy 23:20-22

Complete Jewish Bible

^20 (19) “You are not to lend at interest to your brother, no matter whether the loan is of money, food or anything else that can earn interest. ^21 (20) To an outsider you may lend at interest, but to your brother you are not to lend at interest, so that Adonai your God will prosper you in everything you set out to do in the land you are entering in order to take possession of it.

^22 (21) “When you make a vow to Adonai your God, you are not to delay in fulfilling it, for Adonai your God will certainly demand it of you, and your failure to do so will be your sin.