Leviticus 12:7-8

7He shall offer them before the Lord to make atonement for her, and then she will be ceremonially clean from her flow of blood. “ ‘These are the regulations for the woman who gives birth to a boy or a girl.

8But if she cannot afford a lamb, she is to bring two doves or two young pigeons, one for a burnt offering and the other for a sin offering. In this way the priest will make atonement for her, and she will be clean.’ ”