The Bible views leprosy as a punishment for slander. This association is explicitly indicated by the Biblical juxtaposition of the requirement to observe the leprosy laws with the requirement to remember what God did to Miriam who slandered Moses (See verses Dt24-08:09).

It immediately follows that the leprosy purification procedure is a symbolic exhortation on how to avoid slander.

Using this principle Rashi symbolically analyzes the objects used in the lepor purification procedure as referring to person types:
• The Cedar - refers to a high ranking person;
• The hyssop grass - refers to a low ranking person;
• The sheep (mammal) - refers to a high ranking person;
• The worm - refers to a low ranking person.

The message to the Lepor, the slanderer, is clear. You, the slanderer, must change your attitude. You must realize that the world has a spectrum of people from the low to the high. You can't criticize the low person because that is the way (s)he is suppose to be. You also can't criticize the high person because that is the way (s)he is suppose to be. You must learn to accept every person as being who they are. By conveying this message to the slanderer we remove one aspect of improper attitude which encourages their habit.

Advanced Rashi: The astute reader may have noticed the repetition of the high-low theme in the two pairs: cedar-hyssop, and sheep-worm. we have not dealt with this. We invite the reader to try his own symbolic lenses. One helpful hint advanced by the master of symbolism, Rabbi Samson Raphael Hirsch, is that the cedar and hyssop belong to the plant sphere while the sheep and worm belong to the animal sphere. Here too we have a spectrum. The plant symbolizes a vegatative life of earning a living, eating and reproducing. By contrast the animal symbolizes a social mover. This too is part of the re-education of the slanderer: (S)he must learn to respect both those people who are simple as well as those people who move society.