Leviticus 12:6-8

6"And when the days of her purifying are completed, whether for a son or for a daughter, she shall bring to the priest at the entrance of the tent of meeting a lamb a year old for a burnt offering, and a pigeon or a turtledove for a sin offering,

7and he shall offer it before the Lord and make atonement for her. Then she shall be clean from the flow of her blood. This is the law for her who bears a child, either male or female.

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