Leviticus 12:6-8

6“When the days of her purification are completed for a son or for a daughter, she is to bring to the kohen, at the entrance of the Tent of Meeting, a year old lamb for a burnt offering and a young pigeon or a turtledove, for a sin offering.

7He is to present it before Adonai and make atonement for her. Then she will be cleansed from the discharge of her blood. This is the Torah for her who gives birth, whether to a male or a female child.

8If she cannot afford a lamb, then she is to bring two turtledoves or two young pigeons, one for a burnt offering and the other for a sin offering. Then the kohen will make atonement for her, and she will be clean.”