Leviticus 14:22-23

14:22 and two turtledoves or two young pigeons, which are within his means. One will be a sin offering and the other a burnt offering.

14:23 “On the eighth day he must bring them for his purification to the priest at the entrance of the Meeting Tent before the Lord,

Leviticus 14:31

14:31 a sin offering and the other a burnt offering along with the grain offering. So the priest is to make atonement for the one being cleansed before the Lord.