Deuteronomy 23:20-22

American Standard Version

²⁰ Unto a foreigner thou mayest lend upon interest; but unto thy brother thou shalt not lend upon interest, that Jehovah thy God may bless thee in all that thou puttest thy hand unto, in the land whither thou goest in to possess it.

²¹ When thou shalt vow a vow unto Jehovah thy God, thou shalt not be slack to pay it: for Jehovah thy God will surely require it of thee; and it would be sin in thee. ²² But if thou shalt forbear to vow, it shall be no sin in thee.