Deuteronomy 23:23

23:23 That which is gone out of your lips you shall observe and do; according as you have vowed to Yahweh your God, a freewill-offering, which you have promised with your mouth.
-World English Bible

Other Translation

23:23 That which is gone out of thy lips thou shalt keep and perform; [even] a freewill offering, according as thou hast vowed unto the LORD thy God, which thou hast promised with thy mouth.
-King James Version