Leviticus 12:6; Leviticus 12:8

6 'When the days of her purification are completed, for a son or for a daughter, she shall bring to the priest at the doorway of the tent of meeting a one year old lamb for a burnt offering and a young pigeon or a turtledove for a sin offering.

8 'But if she cannot afford a lamb, then she shall take two turtledoves or two young pigeons, the one for a burnt offering and the other for a sin offering; and the priest shall make atonement for her, and she will be clean.' "