The Gemara asks that both the Chachamim and Rebbi Yehudah contradict their
opinions elsewhere. In the Mishnah in Ma'aseros (3:7, with the explanation
of a Beraisa), the Chachamim state that a Sukah does *not* require a
Mezuzah, while Rebbi Yehudah rules that a Sukah *requires* a Mezuzah! The
reasoning of the Chachamim is because the Sukah is not a permanent dwelling
place, as one lives there for only seven days of the year, and therefore it
does not require a Mezuzah. Rebbi Yehudah, on the other hand, maintains that
even a temporary dwelling is considered a dwelling that requires a Mezuzah.
If so, they contradict their opinions regarding the Lishkas Parhedrin, where
the Chachamim say that it *is* considered a dwelling place to require a
Mezuzah, even though the Kohen Gadol lives there for only seven days out of
the year, and Rebbi Yehudah says it is *not* considered a dwelling place to
require a Mezuzah!
Abaye answers that during the seven days that one lives in the Sukah, and
when the Kohen Gadol lives in the Lishkas Parhedrin, everyone agrees that it
requires a Mezuzah, since one is living there. When Rebbi Yehudah says that
the Lishkas Parhedrin does not need a Mezuzah, he is referring to the
*other* days of the year when the Kohen Gadol is not living there.
Rava challenges Abaye's answer by pointing out that the Mishnah in Ma'aseros
says "Sukas ha'Chag *b'Chag*," clearly implying that the argument between
the Chachamim and Rebbi Yehudah applies even during the seven days that one
lives in the Sukah, in contradiction to what Abaye said.
What is Rava adding by quoting the Mishnah's words, "Sukas Chag *b'Chag*?"
Rava has an obvious question on Abaye even without those words -- that is,
even if the Mishnah is not discussing the period of Sukos itself, there
would be a serious question on Abaye! Regarding Sukah, the Chachamim do not
require a Mezuzah throughout the year, while regarding the Lishkas Parhedrin
they *do* require a Mezuzah throughout the year! Rava should have asked
simply, "Potrin Ketani" or "d'Rebbi Yehudah Kasha k'Rabanan Lo Kasha?" --
the Mishnah says that the Chachamim exempt a Sukah from a Mezuzah and thus
there is still contradiction from Sukah to Lishkas Parhedrin! (TOSFOS DH
Rabanan [the 2nd])
(a) The RITVA explains that Rava was merely asking on the wording of Abaye.
Abaye said that "everyone" agrees that the Sukah, and Lishkas Parhedrin,
require a Mezuzah while one is living there. Rava asks how can Abaye say
that "everyone" agrees -- we find one opinion that maintains that the Sukah
does not need a Mezuzah even while one is living there, and that is the
opinion of the Chachamim in the Mishnah in Ma'aseros.
Rava did not ask how Abaye was reconciling the contradiction between the
Chachamim here, regarding the Lishkah, and the Chachamim there, regarding
the Sukah, because perhaps they are two different sets of Chachamim. The
only contradiction is in the opinion of Rebbi Yehudah, and Abaye's answer
successfully resolves that contradiction. Rava asked that the Mishnah says
"Sukas Chag b'Chag" to show Abaye that it is incorrect to say that *no one*
holds that a Sukah does not need a Mezuzah when one is living there, for we
find that the Chachamim of that Mishnah say that it does not need a Mezuzah.
This seems to be the intention of Rashi (DH v'Ha Sukah) as well.
(b) The RITVA suggests further that perhaps Abaye *was* bothered by the
contradiction in the Chachamim. However, he did not bother answering it
because he held that the Chachamim in the Mishnah in Ma'aseros maintain that
a Sukah is exempt from a Mezuzah only *mid'Oraisa*, but it needs a Mezuzah
mid'Rabanan, and when they say that the Lishkas Parhedrin requires a
Mezuzah, they are referring to a Chiyuv *mid'Rabanan*.
Rava asks that when the Mishnah says that the Chachamim exempt a Sukah from
a Mezuzah, it is teaching the practical Halachah and is not discussing the
d'Oraisa requirement or lack thereof. As such, the Mishnah there implies
that even *mid'Rabanan* a Sukah does not need a Mezuzah, and thus the
contradiction in the opinion of the Chachamim remains unanswered.
(c) TOSFOS (DH Rabanan, #2) and TOSFOS HA'ROSH say that the Girsa in our
Gemara is incorrect. A phrase in Abaye's answer should be reversed; instead
of saying, "Rabanan Savri Gazrinan... v'Rebbi Yehudah Savar Lo Gazrinan," it
should say, "Rabanan Savri *Lo* Gazrinan... v'Rebbi Yehudah Savar
Abaye says that the argument regarding the Lishkas Parhedrin is that Rebbi
Yehudah maintains that it requires a Mezuzah while the Kohen Gadol is living
there because of a Gezeirah that people not think he is incarcerated there.
That Gezeirah extends to the rest of the year, requiring that the Lishkah
have a Mezuzah throughout the entire year, so that, when Yom Kipur comes,
people not think that it is a prison. Therefore, Rebbi Yehudah says that it
requires a Mezuzah all year round because of the Gezeirah. The Chachamim, on
the other hand, maintain that "*Lo* Gazrinan" -- the Lishkas Parhedrin
requires a Mezuzah *not* because of a Gezeirah, but because m'Ikar ha'Din it
is considered a dwelling place that requires a Mezuzah. They hold that there
is no Gezeirah, and therefore there is no reason to make a Gezeirah during
the rest of the year.
Abaye is saying that according to the Chachamim, a *Sukah* does not require
a Mezuzah during the rest of the year, just like the Lishkas Parhedrin does
not require one. According to Rebbi Yehudah, a Sukah *does* require a
Mezuzah during the rest of the year, because of a Gezeirah that people not
say that the Sukah is a prison (which is a disgrace to the Mitzvah), similar
to what he holds with regard to the Lishkas Parhedrin. According to Abaye,
the Mishnah in Ma'aseros is indeed discussing a Sukah during the rest of the
year; Rebbi Yehudah, who is lenient during the time the Sukah is lived in
(requiring a Mezuzah only mid'Rabanan) is stringent during the rest of the
year (again requiring a Mezuzah only mid'Rabanan, so that it not be taken
for a prison). That is the emphasis of his answer. Rava asks that the
Mishnah says "Sukas Chag *b'Chag*."
(d) The NETZIV (MEROMEI SADEH) says that when Abaye says that during the
seven days that one lives in the Sukah everyone agrees that it needs a
Mezuzah, he means that each opinion, the Chachamim and Rebbi Yehudah, is
referring to a Sukah built according to his own specifications. That is,
Rebbi Yehudah maintains that a Sukah may be built in the manner of a
permanent structure. Consequently, he holds that *such* a Sukah requires a
Mezuzah, since it is a regular Dirah. The Chachamim, though, maintain that a
Sukah must be built in the manner of temporary structure, and such a Sukah
is exempt from a Mezuzah even during Sukos itself, since it is not a normal
Dirah. The Lishkas Parhedrin, on the other hand, is a permanent structure,
and therefore it requires a Mezuzah according to everyone, at least while
the Kohen Gadol is living there. Rebbi Yehudah and the Rabanan argue only
whether a Mezuzah is required there during the rest of the year.
Rava asks that according to Abaye's assertion, Rebbi Yehudah should require
a Mezuzah for a Sukah during the rest of the year *if one decides to live
there*. The Mishnah in Ma'aseros, though, says "Sukas Chag *b'Chag*,"
implying that a Sukah needs a Mezuzah when a person lives in it *only*
during Sukos, but during the rest of the year it does not need a Mezuzah
even if one lives there.
Therefore, Rava explains that a Sukah does not need a Mezuzah because it is
not a real dwelling place. The only reason Rebbi Yehudah says that it needs
a Mezuzah is because of the principle of "Achshevei" -- the Torah calls a
Sukah *during Sukos* a dwelling place (Rebbi Yehudah holds that a Sukah may
be a Diras Keva) and thereby makes it necessary to have a Mezuzah, but that
applies only during Sukos.