Leviticus 15:28-31

28When she is cleansed from her discharge, then she shall count off for herself seven days, and after that she will be clean.

29Then on the eighth day she shall take for herself two turtledoves or two young pigeons and bring them to the priest at the doorway of the Tent of Meeting;

30and the priest shall offer one as a sin offering and the other as a burnt offering; and he shall make atonement for her before the Lord for her unclean discharge.’

31“Thus you shall separate the Israelites from their uncleanness, so that they do not die in their uncleanness by their defiling My tabernacle that is among them.”