Deuteronomy 23:23
King James Version
“That which is gone out of thy lips thou shalt keep and perform; a freewill offering, according as thou hast vowed unto the LORD thy God, which thou hast promised with thy mouth.”
Context
20Unto 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.
21When 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.
22But if thou shalt forbear to vow, it shall be no sin in thee.
23That which is gone out of thy lips thou shalt keep and perform; a freewill offering, according as thou hast vowed unto the LORD thy God, which thou hast promised with thy mouth.
24When thou comest into thy neighbour’s vineyard, then thou mayest eat grapes thy fill at thine own pleasure; but thou shalt not put in thy vessel.
25When thou comest into the standing corn of thy neighbour, then thou mayest pluck the ears with thine hand; but thou shalt not move a sickle unto thy neighbour’s standing corn.