Deuteronomy 23:21-23 - Keeping Vows
21 “If you make a vow to the Lord your God, do not be slow to keep it, because He will require it of you, and it will be counted against you as sin. 22 But if you refrain from making a vow, it will not be counted against you as sin. 23 Be careful to do whatever comes from your lips, because you have freely vowed what you promised