THOUGHTS ON THE DAILY DAF
brought to you by Kollel Iyun Hadaf of Har Nof
Rosh Kollel: Rav Mordecai Kornfeld
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1) A "THIRD WALL" WALL FORMED BY A "LECHI"
QUESTION: Rav Kahana made a Sukah by placing Sechach over two perpendicular
walls, with an Achsadrah on the third side. There was no wall on the third
(or fourth) side, but rather there was a pillar that was wider than a Tefach
just outside of the wall that was perpendicular with the opening of the
Achsadrah. From inside the Achsadrah, one could see the pillar just outside
the wall of the Sukah, and it appeared to be the beginning of a third wall,
but it did not extend across the face of the Sukah so that it was not
visible from within the Sukah. Rav Kahana said that since, with regard to
the Halachos of a Mavoy, such a pillar serves as a Lechi (and would permit
carrying inside of a Mavoy), so, too, it serves as a third wall for the
Sukah, and the Sukah is valid.
2) DO THE WALLS OF A SUKAH HAVE TO BE MADE FOR THE PURPOSE OF THE SUKAH
Rav Kahana seems to be invoking the principle of "Migu" -- since it is a
partition for the laws of a Mavoy on Shabbos, it is also a partition for a
Sukah (Daf 7a). This mechanism for considering the Sukah to have a third
wall is problematic.
(a) First, TOSFOS (7b, DH Sikech) maintains that the principle of "Migu" can
only work to fulfill a necessity which is mid'Rabanan. The requirement for a
Sukah to have a third wall is *mid'Oraisa*, and thus "Migu" should not work!
(TOSFOS DH Achvi)
ANSWER: The ROSH answers that in addition to the two walls and the pillar
(Lechi) on the outside of one wall, Rav Kahana's Sukah also had a Tzuras
ha'Pesach along the side with the Lechi. Indeed, we find (7a) that it is Rav
Kahana who maintains that the only time one may use a one-Tefach-wide board
as the Sukah's third wall is when he also built a Tzuras ha'Pesach. In this
case, the Tzuras ha'Pesach makes the Sukah valid mid'Oraisa (because a
Tzuras ha'Pesach is considered a partition), and the Tefach-wide board is
necessary only mid'Rabanan. As such, the rule of "Migu" may be applied to
conclude that since the pillar is effective to fulfill the d'Rabanan
requirement of Lechi for a Mavoy, it is also effective to fulfill the
d'Rabanan requirement to have a one-Tefach-wide board on the third side of
(b) Second, when the Rabanan enacted the requirement for a Mavoy to have a
Lechi at its entrance, they enacted that the Lechi serve as a Heker, a
reminder, but not that it serve as a partition. (Even according to those who
hold that a Lechi is a full-fledged Mechitzah, Eruvin 12b, that is only when
it is in place of the *fourth* wall. Here it is in place of a *third* wall.)
How can Rav Kahana say that since a Lechi serves as a *reminder* when it is
on a Mavoy, it serves as a *partition* for a Sukah?
(c) Furthermore, even if the fact that a Lechi is in *some way* effective
for a Mavoy makes it also effective for a Sukah through Migu, that would
only work if it were effective for a Mavoy with regard to some Halachah
d'Oraisa. Here, though, it merely fulfills a rabbinical requirement for the
Mavoy. How then can it fulfill a d'Oraisa requirement for Sukah? (ROSH 1:34)
Alternatively, the Rosh answers that even if there was no Tzuras ha'Pesach,
the need for the Tefach-wide board was only mid'Rabanan, because mid'Oraisa
the beam of the Achsadrah descended to form the third wall (through "Pi
Tikrah Yored v'Sosem"). Mid'Rabanan, though, that does not suffice, because
the beam of the Achsadrah was not made to serve the outside of the Achsadrah
(where the Sukah is located) but to serve the inside, and thus mid'Rabanan a
third wall of at least one Tefach is required. The "Migu" suffices to
fulfill that requirement.
However, TOSFOS (DH Achvi) asks a fourth question. We learned that whenever
a Sukah is considered to have a wall only because that entity is considered
to be a partition for the laws of Shabbos, it can only serve as a wall for
Sukah *on Shabbos* (Rashi 7a, DH v'Chen l'Shabbos). If so, how did Rav
Kahane's Sukah work during the rest of the days of Sukos?
The ARUCH LA'NER answers that the Rosh is relying on the opinion of the RIF,
who argues with the other Rishonim and maintains that since the "Migu" works
to make the Sukah valid on Shabbos, it also works to make the Sukah valid
during the rest of the week.
QUESTION: The Gemara cites a Tosefta which states that when the Sechach of a
Sukah extends beyond the Sukah ("Pesel ha'Yotzei Min ha'Sukah"), the area
beneath that extension is considered part of the Sukah. Ula explains that
this refers to Sechach which extends over the middle wall of a Sukah, and
the two side walls also extend past the middle wall, so that the extension
of Sechach is actually covering an area surrounded by three walls. The
Gemara asks that since, in this extension, there are three walls, valid
Sechach, more shade than sunlight, it is obvious that it is considered a
valid Sukah! What, then, is the Tosefta teaching?
The Gemara answers that we might have thought that since "it was constructed
for the *inside* of the Sukah, and it was not made to serve the outside of
the Sukah," the extension is not a valid Sukah. RASHI (DH l'Vra'i) explains
that this refers to the middle wall. Since the middle wall was made only to
be a wall for the inside of the Sukah, it cannot count as a wall for a Sukah
constructed outside of the Sukah, from the extension of the Sechach.
From the words of Rashi, it seems that Rashi maintains that the walls of a
Sukah must be constructed for the purpose of the Sukah (according to the
Havah Amina). This is difficult to understand, though, because nowhere in
the Gemara do we find that the walls of a Sukah must be made for the sake of
a Sukah. (Only with regard to Pi Tikrah does Rava apply the logic that Pi
Tikrah can only be applied to walls that were made to serve the Sukah.) On
the contrary, we find in the Mishnah (17a) that the walls of the houses
around an Achsadrah may be used as the walls of a Sukah (through Dofen
Akumah), even though those walls were not made to serve the Sukah.
Because of this problem, TOSFOS (DH l'Vra'i) explains that the Gemara is
referring to the *Sechach*, and not to the wall. Since the Sechach was
placed on the Sukah for the purpose of the inside of the Sukah and not to
serve the outside of the Sukah, we might have thought that the extension is
not valid. Therefore, the Tosefta teaches that it is valid.
How does Rashi answer this question on his explanation?
(a) The RITVA answers that the walls of a house may be used for a Sukah
because they are built to be permanent walls and one has intention to use
them for any purpose for which they will be needed. The walls built
especially for a Sukah, though, are temporary, and we might have thought
that such walls are only valid for the purpose for which they were made
(i.e. the inside of the Sukah).
(b) The PNEI YEHOSHUA answers that in the case of the Mishnah (17a) the
walls of the houses are considered to have been built for the use of the
surrounding porch as well, since the porch is subordinate to the house (and
therefore the Sukah built in that porch can also utilize those walls). Here,
though, the wall was constructed specifically for the purpose of the inside
of the Sukah, and therefore we might have thought that the area outside of
the wall cannot be a valid Sukah.
(c) The ARUCH LA'NER says that indeed, we know from our Mishnah that the
walls of the outside of a house can be used for a Sukah, and in this regard
the Tosefta is teaching nothing new. However, it is the manner of the
Tosefta and Beraisa to teach things that we already learn from the Mishnah.
(d) Perhaps Rashi understands that this case is referring to a Sukah which
has as its middle wall not an actual wall, but only a Halachic wall. That
is, in the place of the wall, there is a row of vertical boards which are
within three Tefachim of each other and is considered a wall only because of
the principle of "Lavud"; alternatively the middle wall does not reach
until the Sechach, and it only serves as a wall due to the principle of "Gud
Achis." Since it is not a real wall but a Halachic one, we might have
thought that "Lavud" and "Gud Achis" works only for the side for which the
partition was constructed (just like the principle of "Pi Tikrah Yored
v'Sosem" does not work with Mechitzos that are not made to serve the Sukah
according to Rava; see Rashi, DH d'Mechitzos and Rashi in Eruvin 95a, DH Lav
l'Sukah). Therefore the Tosefta teaches that such a partition *is*
considered valid even for the area of the extension outside of the Sukah.