Ritual impurity, or tumah, has nothing to do with hygiene. Instead, tumah is a spiritual state that prevents a person from participating in the worship life of the community. One becomes impure through a variety of means, all of which are perfectly natural, such as illness, childbirth, physical
discharges and contact with a corpse. Purity and impurity are not related to good or evil. However, impurity is considered to be a spiritual disability.
For example, tzaraat, the skin affliction that is discussed at length in this part of the Torah, is not the biological disease Leprosy – as it has historically been translated – but rather a state that the Torah understands as the physical manifestation of a spiritual or ritual problem. This is not a medical treatise, nor are the Kohanim (the priests) serving as paramedics. Rather, tumah is a purely ritual concern, and as the ritual leaders of the community, it falls upon the priesthood to facilitate purification for those who find themselves in a state of impurity.
The laws presented in this and the next parasha have long been the basis for numerous rabbinic homilies against the spread of lashon ha-ra — literally “evil speech” or gossip. Metzora, the rabbis conjectured, sounded just like motzi-ra — the bringing forth of evil with the mouth. Cause and effect: if one is guilty of lashon ha-ra, one will be afflicted by tzaraat and thus becomes a metzora. But the Torah tells us that tzaraat is not a permanent condition. One can become healthy again. Neither the condition, nor the sin that precipitated it, is hopeless. There is always the possibility of Teshuva — expiation for one’s misdeed — and a process by which the unclean metzora could again become pure and rejoin the community. This process always exists for us, no matter what our sin was.
Shabbat Shalom – Rabbi Adrian M Schell (Source: R’ JD. Cohen)