Leviticus 12:7-8

New Revised Standard Version, Anglicised Catholic Edition

⁷ He shall offer it before the Lord, and make atonement on her behalf; then she shall be clean from her flow of blood. This is the law for her who bears a child, male or female. ⁸ If she cannot afford a sheep, she shall take two turtle-doves or two pigeons, one for a burnt-offering and the other for a sin-offering; and the priest shall make atonement on her behalf, and she shall be clean.