Biblical Leprosy

In Vayikra (Leviticus) 12:1-15:33, the Scriptues review ritual purity and impurity. After a discussion of the laws of impurity from childbirth, the Word instructs the reader on the diagnosis of Biblical leprosy. There are several views about these passages. Are they referring to a contagious skin disease or something that is inconsistent with a communicable disease? I think the latter makes the compelling case. In support, consider the following:
1. The priests would make his diagnosis only on the parts of the body they could see. There was no examination of the "folds of the body."
2. If leprosy was suspected in a dwelling, the Torah commanded that everything be removed from the house before the examination. This is inconsistent with the handling of a communicable disease. Following this procedure could expose the neighbors to potentially infected material.
3. The laws concerning leprosy applied only to houses in the land of Israel and only after the land had been divided into individual holdings. The laws did not apply to non-Jews or to dwellings of any ownership in the city of Jerusalem.
4. The laws did not apply to non-Jews. Leprosy contracted by a convert before conversion to Judaism was of no consequence.
5. After the nation's entry into the land, the infected person was only excluded from walled cities. He would be allowed to remain in unwalled cities and to roam free. He would not be excluded from the community.

The above points arguably stand for the proposition that something other than sanitary issues were being addressed. What then is Biblical leprosy? Is it natural, physical illness, or supernatural phenomenon? The Talmud lists seven sins that can cause Biblical leprosy: evil speech, murder, perjury, sexual immorality, arrogance, robbery, and miserliness. The rabbis would link the punishment of leprosy with slander, i.e. saying something false about someone, and evil speech, i.e saying something damaging about someone even if it was true. In support, they cite the following:
1. Moses contracts temporary leprosy at the burning bush when he casts aspersions on the Israelites by questioning their desire to respond to God's call to leave Egypt. "And if they do not believe me, nor listen to my voice, and say YHWH has not appeared to you?"
2. Miriam is punished with leprosy when she maligns her brother Moses.
3. According to the passage in Leviticus, leprosy results in the punishment of exclusion from the community. The infected person must distance himself from the community because his words have created distance between couples, friends, or business associates.

A strong case can be made that Biblical leprosy is related to improper speech. Onkelos translated Genesis 2:7 as: "and man became a speaking spirit." We have not fully comprehended the power of words. They have the power to heal, or to kill. Perhaps, they also have a connection to Biblical leprosy. No wonder David said, "Put a guard over my mouth."