Leviticus 5:4-7

4or if anyone thoughtlessly takes an oath to do anything, whether good or evil (in any matter one might carelessly swear about) even though they are unaware of it, but then they learn of it and realize their guilt—

5when anyone becomes aware that they are guilty in any of these matters, they must confess in what way they have sinned.

6As a penalty for the sin they have committed, they must bring to the Lord a female lamb or goat from the flock as a sin offering; and the priest shall make atonement for them for their sin.

7“ ‘Anyone who cannot afford a lamb is to bring two doves or two young pigeons to the Lord as a penalty for their sin—one for a sin offering and the other for a burnt offering.