Leviticus 15:28-31

28When she becomes clean from her discharge, she shall count off for herself seven days; and afterward she will be clean. 29Then on the eighth day she shall take for herself two turtledoves or two young pigeons and bring them in to the priest, to the doorway of the tent of meeting. 30The priest shall offer the 1one for a sin offering and the other for a burnt offering. So the priest shall make atonement on her behalf before the Lord because of her impure discharge.’

31“Thus you shall keep the sons of Israel separated from their uncleanness, so that they will not die in their uncleanness by their 2defiling My 3tabernacle that is among them.”