Deuteronomy 23:20-22

King James Version

²⁰ Unto a stranger thou mayest lend upon usury; but unto thy brother thou shalt not lend upon usury: that the Lord thy God may bless thee in all that thou settest thine hand to in the land whither thou goest to possess it.

²¹ When thou shalt vow a vow unto the Lord thy God, thou shalt not slack to pay it: for the Lord 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.