The hideous and hopeless nature of this disease—which is nothing short of a foul decay, arising from the total corruption of the blood—has been too often described to need further notice. See Leviticus 13, 14. It was a living death, as indicated by bare head, rent clothes, and covered lip. In the middle ages, a man seized with leprosy was “clothed in a shroud, and the masses of the dead sung over him.” In its horrible repulsiveness it is the Gospel type of Sin. The expression “full of” implies the rapid development and horror of the disease; when the man’s whole body was covered with the whiteness, he was allowed to mingle with others as clean (Leviticus 13:13).
The faith of this poor leper must have been intense, for hitherto there had been but one instance of a leper cleansed by miracle (Luke 4:27; 2 Kings 5).
In order to prevent the accidental violation of this law, lepers, until the final stage of the disease, were then as now secluded from all living contact with others, “differing in nothing from a dead man” (Jos. Ant. iii. 11 § 3), and only appeared in public with the cry Tamê, Tamê—‘Unclean! Unclean!’
But Jesus, “because He is the Lord of the Law, does not obey the Law, but makes the Law” (St Ambrose); or rather, he obeys that divine eternal Law of Compassion, in its sudden impulse, which is older and grander than the written Law. (So Elijah and Elisha had not scrupled to touch the dead, 1 Kings 17:21; 2 Kings 4:34.) His touching the leper, yet remaining clean, is a type of His taking our humanity upon Him, remaining undefiled.
Our Lord’s first miracles were done with a glad spontaneity in answer to faith. But when men had ceased to believe in Him, then lack of faith rendered His later miracles more sad and more delayed (Mark 6:5; Matthew 13:58). We never however hear of a moments delay in attending to the cry of a leper.
Jesus was not polluted by the touch, but the leper was cleansed. Even so he touched our sinful nature, yet without sin (H. de St Victore).
[Excerpt from the Cambridge Bible for Schools and Colleges]
While he was in one of these villages, a man with a skin disease all over his body came to Creator Sets Free (Jesus). He humbled himself, bowed down and pleaded with him. "Honored One!" he cried. "If you want to, you can heal and cleanse me."
Creator Sets Free, stirred with compassion, reached out and touched the man. "I want to!" he said. "Be cleansed!" And right away the disease left him and he was healed. Luke 5:12-13 FNV