Charles Ellicott Commentary Leviticus 14:12

"And the priest shall take one of the he-lambs, and offer him for a trespass-offering, and the log of oil, and wave them for a wave-offering before Jehovah:" — Leviticus 14:12 (ASV)

And offer him for a trespass offering. —As leprosy was a Divine punishment for sin, the restored leper had to bring expiatory sacrifices. There is, however, a striking difference in the ritual of the leper’s trespass offering and the ordinary trespass offering described in Leviticus 5:6 and following. In the case before us, not only did oil accompany it, but both the trespass offering and the oil were waved by the priest, which did not take place on any other occasion in connection with the trespass offering and sin offering. Indeed, in no other case was the entire victim waved before the Lord.