What is the background for the "leprosy laws"?
In Leviticus 13 God is giving the laws concerning leprosy to Israel. But instead of talking about leprosy it talks about a leprosy (v 8,15). Does that mean that leprosy is a synonym for disease (i.e. a generic term for unclean scabs/boils etc)? But then it also talks about a plague of leprosy. Does that mean that there are different types of leprosy? And what was the difference, why sometimes they had were unclean, and sometimes they weren’t? What is the "background" for these laws?
I don't profess myself an expert on any of these detailed laws of leprosy and the many other Mosaic details on diseases. Yet as there are many varieties of cancer which ultimately are still all the same disease, so there may have been different forms of leprosy. At least it appears that there were different stages of development in leprosy. From what I have read elsewhere, I don't think you must consider leprosy' as a generic term for boils and scaps, warts and other skin irritations. Leprosy was definetely a disease on its own. It is still very found in countries like India where there are leprosy colonies. Modern medicines has diagnosed it but I don't think has found a definite cure for it. Recently I read a book by a late leprosy doctor who did have quite a succes rate in treating and helping leprosy sufferers. God chose leprosy also for spiritual reasons. The disease makes a person's body 'slowly rot away.' It cause ligaments to fall off, noses to be eaten away and the leprosy suffers smells like death. Perhaps because of the nature of the disease did the Lord select this one as a spiritual representation of what sin does to us. Eventually the leper was excluded from normal society, even separated from wife and children. Isn't that a picture of what ultimately sin will do to us? It will bring us into hell where we will share the same fate in the same place without any real connection or comfort. The only way a leper could completely be cured was by God Himself; a miracle would have to take place. Jesus healed many lepers and that was clearly a message in itself also. Again, that illustrated the message of the Bible! Only God is able to cure the sinner; nothing of man comes into this. It is all His grace, His power, His Spirit, His blood and His thought! Soli Deo Gloria.
What is interesting about these leprosy laws is something that we didn't discover till the late 1800's! How did Moses know that leprosy is contagious but only 'airborne.' Not by touch but through the sneezing or even breathing. God told the leper to cover his mouth and nose with his hand and cry 'unclean' when someone come too close! You know why God commanded that. Moses had no clue that there was a medical reason to this hand! It provides us with another powerful proof of the Divine inspiration of Scripture. God's Word is about 3500 years ahead of modern science!