Deuteronomy 23:23-25

New Catholic Bible

²³ But if you fail to make a vow, there is no sin. ²⁴ Whatever your lips utter, you must do, for you have vowed a freewill offering to the Lord, your God, with your own mouth.

²⁵ If you enter your neighbor’s vineyard, you can eat as many grapes as you want, but you are not to put any in a basket.