Ecclesiastes 5:4-6

New Revised Standard Version, Anglicised Catholic Edition

⁴ When you make a vow to God, do not delay fulfilling it; for he has no pleasure in fools. Fulfil what you vow. ⁵ It is better that you should not vow than that you should vow and not fulfil it. ⁶ Do not let your mouth lead you into sin, and do not say before the messenger that it was a mistake; why should God be angry at your words, and destroy the work of your hands?