Leviticus 14:29
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 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.
Leviticus 14:1-32 lays out the priestly procedure for declaring a leper clean, and verse 29 directs the priest to put the rest of the oil that is in his hand upon the head of him that is to be cleansed, to make an atonement for him before the Lord. That rite belongs to the Mosaic law for a person cleansed of leprosy. The broader cleansing law for a healed leper requires going to the priest, showing himself for thorough examination, receiving a public pronouncement that he is entirely free from infectious disease and in sound health and may safely return to family and friends, and then presenting the offering Moses commanded.
Jesus directed the healed leper to follow Moses' instructions and present to the priest the required offering for cleansing. He required the cleansed man to go to the priests with the offering required by Moses' law for the cleansing of a leper. That direction upheld, respected, and sanctioned the law of Moses and the Jewish code. It showed that Jesus did not oppose the law of Moses, refuted the accusation and charge that He and His teaching were opposed to the law, and proved to the people that His teaching was not opposed to it.
The required priestly examination and decision confirmed freedom from disease and fitness to return to family and friends, and its certification of the cure stood as a testimony to the priests. That testimony convinced them of His divine power even while they refused Him as Messiah, and became a public testimony to Christ's power. The cleansing ceremony was a shadow of events fulfilled in Christ, and His death brings its significance to light, when type met antitype.