It is better not to vow than to make a vow and not fulfill it.

Acts 5:4
Did it not belong to you before it was sold? And after it was sold, was it not at your disposal? How could you conceive such a deed in your heart? You have not lied to men, but to God!"

Deuteronomy 23:21
If you make a vow to the LORD your God, do not be slow to keep it, because He will surely require it of you, and you will be guilty of sin.

Judges 11:35
As soon as Jephthah saw her, he tore his clothes and said, "No! Not my daughter! You have brought me to my knees! You have brought great misery upon me, for I have given my word to the LORD and cannot take it back."

Proverbs 20:25
It is a trap for a man to dedicate something rashly, only later to reconsider his vows.

Jonah 2:9
But I, with the voice of thanksgiving, will sacrifice to You. I will fulfill what I have vowed. Salvation is from the LORD!"

Better is it that you should not vow, than that you should vow and not pay.