Ecclesiastes 5:4-6 NIV

[4] When you make a vow to God, do not delay to fulfill it. He has no pleasure in fools; fulfill your vow. [5] It is better not to make a vow than to make one and not fulfill it. [6] Do not let your mouth lead you into sin. And do not protest to the temple messenger, “My vow was a mistake.” Why should God be angry at what you say and destroy the work of your hands?