POINT BY POINT SUMMARY
by Rabbi Ephraim Becker
Kollel Iyun Hadaf, Yerushalayim
Rosh Kollel: Rabbi Mordecai Kornfeld
Ask A Question on the daf
Previous dafSukah 18
1) COMBINING SHIURIM (cont'd)
(a) Question: If a four-Tefach plank always invalidates a
Sukah, then why does R. Meir, in the Beraisa, allow
S'chach when there is an equal amount of space as the
Pasul boards between each board?!
2) LAVUD LE'HACHSHIR
(b) Answer (R. Huna b.R. Yehoshua): That Sukah has a unique
configuration which allows for an eight-Tefach Kosher
Sukah in the middle.
1. The alternating board-open, board-open takes place
three times from each side of an eight-Amah-wide
Sukah (the 'open' from each side meet in the
2. The boards are, indeed, S'chach Pasul, but they
are within the four Amos limit for Dofen Akumah,
leaving an eight Tefach Kosher Sukah.
(a) (Abaye) If one diminishes a three Tefachim open space
(with either Kosher or non-Kosher S'chach) in a Sukah
larger than the minimum, the Sukah is Kosher.
3) HALACHOS OF R. YEHUDAH B. IL'AI
1. There is neither the Shiur of space nor that of
S'chach Pasul to invalidate it.
(b) The above applies when the open space is next to the
2. If one did the same thing in a minimum Sukah it
would be Pasul, because it does not have the Shiur
S'chach for a Sukah.
3. If one filled in part of the space with canes, the
minimum Sukah is Kosher, because of the principle
(c) R. Acha and Ravina argue what the Din will be in the
middle of the Sukah.
1. (Ravina) We would apply Lavud in the middle of the
Sukah, as well.
(d) Question: What is the rationale for Ravina?
2. (R. Acha) Lavud is applied only next to a wall.
(e) Answer: He applies the leniency found by the Koreh of a
1. To carry in a Mavui requires (either a Lechi at
the entrance or) a Koreh across the entrance of
(f) Question: Why, then, would R. Acha not allow Lavud in
2. If the beam is interrupted in its middle by a
space of up to three Tefachim, it is a valid Koreh
(g) Answer: This is restricted to the beams of a Mavui,
whose application is mi'de'Rabanan, as we see in the
Beraisa where, when dealing with Tumah d'Oreisa, Lavud
does not 'close up' a small skylight.
(h) Question: How will Ravina understand this Beraisa?
(i) Answer: Hilchos Tumah have unique specifications (the
Halachah l'Moshe mi'Sinai is that regarding Tumah,
there is no Lavud in the middle).
(a) (R. Yehudah b. Il'ai) A skylight covered with S'chach
(b) (R. Yishmael b.R. Yosi) My father taught that this only
applies up to four Amos from the walls (Dofen Akumah).
(c) (R. Yehudah b. Il'ai) A type of small fish called
Abruma is permitted.
(d) (R. Yishmael b.R. Yosi) My father taught that its
Kashrus depends on which river it is drawn from (some
rivers grow insects, etc).
1. (Abaye) A type of small fish called Tzachnasa from
the River Bav is permitted.
2. Question: Why are we not concerned that this small
fish will be interchanged with Tameh fish?
3. Answer: Because the Bav is a swift-flowing river
and non-Kosher fish, which have no spinal cord,
could not survive in it.
4. Question: But we find non-Kosher fish in other
5. Answer: It is because the waters of the Bav are
very salty and non-Kosher fish, which have no
scales, could not survive in it.
6. Question: But we find non-Kosher fish in salty
7. Answer: It is because the mud on its river-bed is
inhospitable to insects, and non-Kosher fish.
8. (Ravina) Fish from the Bav are now no longer
permitted because the waters of other rivers,
which bring insects with them, flow into it.
4) THE COURTYARD WALLS AND PI TIKRAH YORED VESOSEM
(a) The walls of a Sukah may be made by uprights placed
less than three Tefachim apart (Lavud).
1. This is taught regarding the case in the Mishnah
of three walls created by the houses facing into
(b) (Abaye) The Sukah is allowed even without the uprights,
as we apply Pi Tikrah Yored veSosem to create inner
walls from the ceilings which surround the courtyard.
2. There we learned that if the overhanging roof
extends more than four Amos into the courtyard,
the house walls cannot serve as the walls of the
Sukah, and it does not suffice to put S'chach over
the open area beyond the overhang.
(c) (Rava) We do not apply Pi Tikrah Yored veSosem in this
(d) Question (Rava): If Pi Tikrah indeed creates walls then
it should create a wall and close the third wall of a
Sukah, as well (where we only have two parallel walls
and boards for S'chach between them)!?
(e) Answer (Abaye): Abaye concedes that Pi Tikrah Yored
does not apply in such a Sukah, as the Rabanan forbade
it because it resembles an open Mavui.
(f) Question: Shall we suggest that Rava and Abaye are
arguing in the Machlokes Rav and Shmuel?
1. (Rav) It is permitted to carry on Shabbos inside
an Achsadra that is not near a house because Pi
Tikrah Yored veSosem (even by all walls).
(g) Answer: There is no Machlokes Abaye and Rava within the
view of Shmuel, and even Rava will agree that Shmuel
will forbid our Achsadra without uprights.
2. (Shmuel) One may not carry beyond four Amos.
3. Abaye who permits an Achsadra without uprights
seems to be like Rav, while Rava is like Shmuel
who does not say Pi Tikrah on four sides (only on
1. The Machlokes Abaye and Rava is regarding the
opinion of Rav.
2. Abaye permits the Sukah according to Rav.
3. Rava (who concedes that a field-Achsadra allows
for Pi Tikrah) holds that the allowance there is
because the roof (and, by extension, the Gud Achis
walls) were made for the sake of a Sukah.
4. But by the Sukah in the courtyard, the overhangs
were not made for the Sukah, and Pi Tikrah will
thus not apply.