Leviticus 13:3
And the priest shall look on the plague in the skin of the flesh: and when the hair in the plague is turned white, and the plague in sight be deeper than the skin of his flesh, it is a plague of leprosy: and the priest shall look on him, and pronounce him unclean.
The verse places the duty to look upon a suspected plague in the skin of the flesh with the priest, who must examine the case and decide whether the person is unclean. His examination comes after physicians have examined it and found the disease incurable and baffling, with noted physicians making a thorough examination and finding it a fatal disease. The signs he looks for are the hair in the affected area turning white and the plague appearing deeper in sight than the surrounding skin.
When those signs are present and the worst form of leprosy is found, the priest declares the sufferer unclean. That declaration of uncleanness is dreaded, for the loathsome disease makes the person contaminate those within touch of him. The ruling shuts the person out from intercourse with others, requiring separation and exile from family, friends, home, and the congregation and society in which he lived.
The verdict is a sentence to a living death. The isolated person is restricted to the company of other lepers, so that even a king has to leave society. The sentence can remove someone of high distinction from the society in which he held that standing and drive him out as an exile from his home. Among the Jews leprosy was regarded as a judgment for sin and served as a symbol of sin.
A healed person has to present himself to the priests for examination and an official decision before he can return to his community. When cleansed by the compassionate touch and power of the Saviour, the curse no longer contaminates others, and the person joins the rejoicing procession for Jesus and lays untainted garments in His path in thanksgiving.