Ecclesiastes 5:4-7

When you make a vow or a pledge to God, do not put off paying it; for God takes no pleasure in fools [who thoughtlessly mock Him]. Pay what you vow. [Ps 50:14; 66:13, 14; 76:11] It is better that you should not vow than that you should vow and not pay. [Prov 20:25; Acts 5:4] Do not allow your speech to cause you to sin, and do not say before the messenger (priest) of God that it was a mistake. Why should God be angry because of your voice (words) and destroy the work of your hands? [Mal 2:7] For in a multitude of dreams and in a flood of words there is worthlessness. Rather [reverently] fear God [and worship Him with awe-filled respect, knowing who He is].