Leviticus 5:4-6

DouayRheims(i) 4 The person that sweareth, and uttereth with his lips, that he would do either evil or good, and bindeth the same with an oath, and his word: and having forgotten it afterwards understandeth his offence, 5 Let him do penance for his sin: 6 And offer of the flocks an ewe lamb, or a she goat, and the priest shall pray for him and for his sin.