The Law provided detailed help for the priests in determining the impact of the spread of a wide range of infectious conditions. There were a variety of skin diseases thrown into the leprosy category. There were also mold conditions within a dwelling that would render it unlivable and unclean. The priests were trained in the proper diagnosis of these conditions. And they did not offer any healing. They did offer a response if God should chose to heal the individual.
In the case of the leper, he was supposed to show himself to the priest who would then begin the process of determining if the leprosy had indeed stopped its progress. Jesus referred lepers that He had completely healed to this procedure. It restored a condition of ceremonial cleanness to the leper so that participation in the life of worship and the society of God’s people could continue. Jesus advocated this practice when He completely healed lepers (Matthew 8:4). It was the way in which the society knew beyond any doubt that God had worked.
So a leper was twice cleaned when God healed him. He was cleansed of the ravages of a disease, and He was purified for worship of the Lord. This required God’s work, his cooperation, and the work of the priest. But in the end, his physical and his spiritual life were no longer those of a misfit or outcast. The physical disease was symbolic of a greater spiritual problem. Both of those issues were met by the Law. And the result was that the holiness of God was magnified. No physician could take credit for the healing when ultimately the priest would determine the man’s readiness to be united to God through the worship at His altar. God got the glory through the physical healing and the spiritual restoration. Sadly, until Jesus, we do not see many Old Testament accounts of this happening. There is the story of Moses’ sister Miriam being struck with leprosy and eventually being healed (Numbers 12:15). There is the story of Naaman (2 Kings 5). It took Jesus to truly make lepers whole.