Leviticus 14:29-31

and the rest of the oil that is in the priest's hand he shall put upon the head of him that is to be cleansed, to make an atonement for him before the LORD. And he shall offer the one of the turtledoves, or of the young pigeons, such as he can get; even such as he is able to get, the one for a sin offering, and the other for a burnt offering, with the meat offering: and the priest shall make an atonement for him that is to be cleansed before the LORD.