כ׳ בתמוז ה׳תש״ע (July 2, 2010)

Shevu’ot 5a-b – Defining biblical leprosy

The Mishnah (2a) described that marot nega’im – biblical leprosy – are “two that are four.” That is to say that the two nega’im – the two signs of plagues of leprosy mentioned in the Torah (see Vayikra 13:1-2) – a se’et or a baheret – each have toladot – other, lower level signs of this plague – that are similar to them in color. Our Gemara quotes a Mishnah in Masechet Nega’im that teaches that a se’et is the color of white wool, and its toladah is the color of the membrane of an egg. A beheret is the color of snow and its toladah is the color of the lime that was used to paint the Temple sanctuary.

 

Rabbi Hanina notes that this Mishnah disagrees with Rabbi Akiva who rules that the different shades of white are hierarchical which will not allow a nega that is the color of lime to be joined with another nega to be the appropriate size.

 

There are two main explanations in the rishonim regarding this disagreement.

According to Rashi, the author of our Mishnah and the Mishnah in Nega’im believes that there are two categories – se’etand baheret – each of which has a related nega one step lower that the main nega. The nega’im in each category can be joined to establish a full nega tzara’at. Rabbi Akiva, on the other hand, does not see a number of categories, but one list of nega’im, and each one can only be joined to a nega that is right next to it on the hierarchy.

The Ramban and others view the disagreement differently. They believe that even Rabbi Akiva agrees that the different nega’im can be joined to each other. They argue that the difference is one of definition. of the Mishnah believe that the two categories of se’et and baheret are not simply two different levels of the same color, but are essentially different shades of white, and each of those shades has a second level nega that is similar to it. According to Rabbi Akiva, however, there is only one shade of white and the four nega’im are different levels of whiteness.