Avulei demechusa, not for entering the city but for the Dira in the wall ! Compare: eruvin daf 6b: if doors not closed, Reshut Harabim, Rashi, 600000 entering ?
David Taqqu, Switzerland
Rashi here DH Abuli writes that Abuli deMechuza are the gates of Mechuza, and in Eruvin 6b Rashi DH Abuli also writes that they are the gates of that city. In Yoma 11a Abaye asked Rav Safra why did the Rabbis not put a Mezuzah on those gates? The question was that since the Torah states (as we say every day in Keriyas Shema) that there is a Mitzvah to fix a Mezuzah on the gates, why then do the gates of Mechuza not have a mezuzah? One should need a Mezuzah not just for the Dira in the wall itself, but for all of the 600,000 people living in Mechuza?!
Shabbat Shalom
Dovid Bloom