Leviticus 12:6, 8

“ ‘When the days of her purification for a son or daughter are over, she is to bring to the priest at the entrance to the tent of meeting a year-old lamb for a burnt offering and a young pigeon or a dove for a sin offering.

But 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.’ ”