Leviticus 14:18
And the remnant of the oil that is in the priest’s hand he shall pour upon the head of him that is to be cleansed: and the priest shall make an atonement for him before the LORD. And the remnant of the oil that is in the priest’s hand he shall pour upon the head of him that is to be cleansed: and the priest shall make an atonement for him before the LORD.
Leviticus 14:18 belongs to the ceremonial law for a person cleansed of leprosy, prescribing that the remnant of the oil in the priest's hand be poured upon the head of the one to be cleansed while the priest makes atonement for him before the Lord. Leprosy made a person unclean and separated from family, friends, and Israel's congregation. The cleansing law in Leviticus 14:1-32 required the healed person to go to the priest, be thoroughly examined and pronounced entirely free from the infectious disease and in sound health, and then present the offering Moses commanded, with the priest completing the prescribed rite. As part of that ceremonial system, its ceremonies were shadows whose meaning was fulfilled when Christ died.
Jesus obeyed this law and directed the healed leper to obey it by appearing before the priest — the same priests who had banished him — and presenting the prescribed cleansing offering. That direction showed respect for the law, sanctioned its requirement, and proved that his healing and teaching were not opposed to Moses' law or the Jewish code. The priest's examination and public certification confirmed the cure and restored the man to family, friends, and Israel's congregation. Giving the priests an opportunity to examine the cure that they could not evade, it stood as irrefutable, lasting testimony to Jesus' divine power and love and against the charge that he opposed the law, even though they still refused him as Messiah.