Leviticus 5:6-7

6He shall also bring his guilt offering to the Lord for his sin which he has 1committed, 2a female from the flock, a lamb or a 3goat as a sin offering. So the priest shall make atonement on his behalf for his sin.

7‘But if 4he cannot afford a lamb, then he shall bring to the Lord his guilt offering for that in which he has sinned, two turtledoves or two young doves, 5one as a sin offering and the other as a burnt offering.