Leviticus 5:4-6

4A person is doing a wrong thing if he says any careless promise. The promise might be good or bad. People will tell him that he has not obeyed God's rules. Then he will know that he has sinned.

5A person must tell the priest if he has done any of these things.

6He must give a sheep or a goat for a sin offering. Then the Lord will not be angry with him. The priest will kill the animal as a sacrifice to atone for that sin.