In this week’s Torah portion we learn about the Tzoraas affliction which was a form of leprosy that a person contracted as a punishment for speaking ill about other people. The Torah specifies the precise color and other signs for us to ascertain that it is in fact the Tzoraas leprosy. If the leprosy matched the Torah’s criteria, then the Kohen (Priest in the Temple) would announce that the person is impure. The person would then have to be separated from the community and remain outside the Jewish camp until the leprosy went away.
The Torah tells us that the person does not become impure unless the Kohen announces that he is impure. Even if there is an expert in the laws of the Tzoraas leprosy who declares the person impure, it does not suffice. This begs the question: there are other forms of impurity that the Torah teaches about, yet, we do not need a Kohen to ascertain that the person is impure. Why in the case of the Tzaraas leprosy in particular is a Kohen needed?
The commentaries explain that the Tzaraas impurity was a very severe impurity as can be seen from the fact that the person must be totally separated from other people. Therefore, the Torah states that the Kohen must be the one who decides if the person is impure. Recent studies have shown that people who are Kohen have their own distinct genes. This correlates to what the Torah teaches that a Kohen has distinct qualities, one of them being kindness and good heartedness. Therefore, the Kohen is the right person to decide if the person is impure, since, we can be sure that he will not leave any stone unturned trying to find a reason not to declare the leper impure.