Leviticus 5:4-6

“ ‘Or someone might make a promise before the LORD without thinking. It might be a promise to do something bad or something good; it might be about anything. Even if he forgets about it, when he remembers, he will be guilty. “ ‘When anyone is guilty of any of these things, he must tell how he sinned. He must bring an offering to the LORD as a penalty for sin; it must be a female lamb or goat from the flock. The priest will perform the acts to remove that person’s sin so he will belong to the LORD.