Why were there less zav, zavahs, and niddahs in Yerushaliyim than other places? Seemingly there should have been the same proportion in Yerushaliyim.
Avraham Sacks, Ramat Beit Shemesh
The Mishnah in Taharos 4:5 says that Chazal decreed that all Safek Rukin have a status of Tamei, and our Mishnah excludes Yerushalayim from this sweeping Gezeirah.
The Tiferes Yisrael writes that Yerushalayim was unique because, unlike the rest of world where we assume there is a Mi'ut ha'Matzui (significant minority) of Zavim , Zavim were a Miut she'Eino Matzui (insignificant minority) in Yerushalayim. Therefore the Gezeirah applies to the rest of the world in line with the common practice mi'd'Rabanan of not relying on Rov when there is a Mi'ut ha'Matzui. We usually assume that a Mi'ut ha'Matzui is ten percent and up according to the Mishkenos Ya'akov.
Avraham Phillips
Thank you for your help and time.
You wrote that according to the Tiferes Yisroel there was a Mi'ut she'Eino Matzuy in Yerushalayim unlike the rest of the world where we assume there is a Mi'ut ha'Matzuy of Zavim. Why, though, would there be a different percentage of zavahs and niddahs in Yerushalayim than anywhere else? Seemingly at least with niddahs, and I assume with zavim as well, it is according to tevah.
Thank you again for your help,
Avraham Sacks
The Ha'Gahah on the Rosh in Maseches Taharos 5:8 in the name of Rabeinu Menachem says that they were more careful about Tum'ah in Yerushalayim due to it's elevated Kedushah. The Meiri suggests that Nochrim weren't commonly found in Yerushalayim.
The Rabeinu Menachem's reason seems to be that many of the people in Yerushalayim, residents as well as visitors, were involved with the Mikdash in one way or another. On any given day, there were many Kohanim and Levi'im who served in the Mikdash as well as people who came to bring Korbanos, and they were likely to undergo Taharah at the first available opportunity if they became Tamei. In other places, aside from Kohanim who ate Terumah, there was less pressure to be Metaher oneself immediately other than prior to Yom Tov when there is a Mitzvah to be Metaher oneself.
Avraham Phillips