The major portion of today’s Parsha deals with Tzara’as - usually translated as leprosy. However, this is incorrect. Rabbi Shimshon Rafael Hirsh explains that the diagnosis and treatment of Tzara’as is completely different than leprosy.
Firstly - Leprosy begins with a darkening of the skin and swelling. Tzara’as is white and no swelling.
Secondly - The worst type of Tzara’as - boils of Egypt – does not render anybody impure.
Thirdly - Raw flesh within a diseased area is impure. However, if the healthy flesh disappeared and Tzara’as returned to that spot, the person was pure. Leprosy would have the opposite diagnosis.
Fourthly - the Kohein only examined those parts of the body that the eye can easily see. Hidden folds were not examined. The kohein’s decision of pure or impure was based upon appearance, and not upon a thorough physical examination.
Fifthly - Before the kohein examined a house that was suspected of being plagued, all objects were removed from that house. No person was examined during Sheva Brachos, Shabbos or Yom Tov.
No house in Jerusalem could be declared impure. A Metzora – leper - was allowed to remain in an unwalled city. A non-Jew could not be declared impure even if he/she converted while plagued. If the Torah was worried about the spread of this disease, none of this would be true.
An unusual rule about the Metzora is that his fate could only be determined by a Kohein. The Metzora went to the Kohein and the Kohein examined him unless it was the week of his Sheva Brachos or Yom Tov. Then the Kohein would tell him to come back after the event was over. It was up to the Kohein to determine if the person standing in front of him was pure or impure. Nobody besides a kohein could render a decision about the Metzora.
That is quite strange! Let us say a Metzora would come. He would ask Moshe Rabbeinu, the Rambam, the Vilna Gaon, The Ba’al Shem Tov or Rav Moshe Feinstein for a halachik descision, their ruling would be worthless! Why is it that the greatest scholars in Israel are unable to render a halachik descision in this instance?
The Kohein dealt regularly with matters of purity and impurity. He handled the service in the Bais Hamikdash. In order to enter the Bais Hamikdash, a kohein must be pure. In order to perform the service, a kohein must be pure. The kohein knew the feeling of impurity and helplessness that accompanied it. He was able to sympathize with the metzora and would try his best not to declare the person impure. The greatest scholars in Israel did not necessarily have that same feeling. They were not involved in the service of the Bais Hamikdash. They did not have to be there on a regular basis. They were not in the same mindset as the metzora. Therefore, the Kohanim were better qualified to render this decision. They understood the feeling of a Tamei ache.