Leviticus 15:29-31

New Revised Standard Version, Anglicised Catholic Edition

²⁹ On the eighth day she shall take two turtle-doves or two pigeons and bring them to the priest at the entrance of the tent of meeting. ³⁰ The priest shall offer one for a sin-offering and the other for a burnt-offering; and the priest shall make atonement on her behalf before the Lord for her unclean discharge.

³¹ Thus you shall keep the people of Israel separate from their uncleanness, so that they do not die in their uncleanness by defiling my tabernacle that is in their midst.