Seder 84: Lev 13---Ritual Impurity from a Skin Condition

 Old Testament scholar Richard Hess has pointed out that Leviticus 13 belongs to a genre not often seen in ancient sources, the Bible in particular:  an algorithm.  

The algorithm in Lev 13 is a procedure to be followed by Israel's high priest in identifying whether a person has a skin condition that would render that person ritually impure.  The procedure includes questions like:  Is the condition spreading? Is there discoloration?  Is the condition more than superficial?  Does it cover part, but not all, of the person?  Affirmative answers could lead to a decision that the person was ritually impure.  

Commentators have a number of suggestions on what kinds of skin conditions are in view in Lev 13.  Our English translations use the word "leprosy", derived from the Greek word lepra, which was used for a number of skin conditions.  The condition we now call "leprosy", Hansen's disease, was not one of them.  As far as we know, Hansen's disease did not reach that part of the world until the second century BC, and its symptoms do not seem to match the description in Lev 13.  (Thiessen has a good discussion of this in his book.)

As with other kinds of ritual impurity, there was a connection with death.  A person with this kind of condition, involving lots of flaking skin, looked a little bit like a zombie.  The key factor seems to be how the person's skin looked.  

Commentators point out that the high priest was not acting in a medical capacity in implementing this algorithm.  If the person was declared impure, that person was not being quarantined for a disease.  The conditions in view here are not highly contagious.  In fact, if the condition completely covered the person, which could be a big problem medically, the person would not be considered ritually impure (vv 12-13).  

There are three examples recorded in scripture where a person was divinely punished for a serious sin with this kind of condition:  Miriam in Num 12; Gehazi in 2 Kings 5, and King Uzziah in 2 Chron 26. 

I would argue that these special cases do not reflect the usual situation being described in Lev 13, for three reasons:

1. Leviticus 13 does not say that the condition was a punishment for sin. 
2. Other kinds of ritual impurity involve things that happen in life rather than sins.
3. There would be no need for the algorithm laid out in Lev 13 if this condition were usually a divine punishment.  In the three special cases mentioned above, the fact that they had this kind of condition was obvious to everyone.