Leviticus 5:6-10

6Then he is to bring his trespass offering to Adonai for his sin that he committed: a female from the flock, a lamb or a goat, as a sin offering. So the kohen is to make atonement for him over his sin.

7“But if one cannot afford a lamb, then he shall bring, as his trespass offering for the sin he committed, two turtledoves or two young pigeons, to Adonai. One is for a sin offering and the other for a burnt offering.

8He is to bring them to the kohen, who will present the one for the sin offering first, and twist its head from its neck but not sever it completely.

9He is to sprinkle some of the blood of the sin offering on the side of the altar, while the rest of the blood is to be drained out at the base of the altar. It is a sin offering.

10He is to make the second a burnt offering, according to the regulation. So the kohen is to make atonement for one over his sin that he committed—and he will be forgiven.