Leviticus 5:6-7

⁶and he shall bring his trespass offering to the LORD for his sin which he has sinned: a female from the flock, a lamb or a goat, for a sin offering; and the priest shall make atonement for him concerning his sin.

⁷“‘If he can’t afford a lamb, then he shall bring his trespass offering for that in which he has sinned, two turtledoves, or two young pigeons, to the LORD; one for a sin offering, and the other for a burnt offering.