Leviticus 5:7-10

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. 8They are to bring them to the priest, who shall first offer the one for the sin offering. He is to wring its head from its neck, not dividing it completely, 9and is to splash some of the blood of the sin offering against the side of the altar; the rest of the blood must be drained out at the base of the altar. It is a sin offering. 10The priest shall then offer the other as a burnt offering in the prescribed way and make atonement for them for the sin they have committed, and they will be forgiven.