PARTS OF A BED BEING MEKABEL TUM'AH
Question: In what Mishnah do we find the position of R. Chanan citing Rebbi?
Answer: It is a qualification of Chachamim in the Mishnah in Kelim dealing with the Tum'ah and Taharah of parts of a bed.
(R. Eliezer): Only a complete bed is subject to Tum'ah.
(Chachamim): Sections of it can become Tamei (and Tahor) independently.
Question: In what manner will parts be Tameh according to Chachamim?
Answer (R. Chanan citing Rebbi): Such as one length of bed with its two legs, or one width with its two legs.
Question: What is that good for?
Answer: One can attach ropes to it and then lean it against the wall and sleep on it.
WORN OUT KELIM
Question: What are the worn out Kelim which R. Ami b. Tivyumi referred to as being Sechach Pasul?
Answer: Clothes of less than the minimum size garment (3x3 Etzba'os).
The Beraisa which invalidates the worn out grass mats from being Sechach supports R. Ami b. Tivyumi (parenthetically, a large mat which was made as Sechach is Kosher while a smaller mat, made for sleeping, is not valid as Sechach.
A SUKAH CUT FROM WITHIN A HAYSTACK
(R. Huna): The Pesul of the Mishnah is only if there is no Tefach-deep (and 7x7 Tefachim large) hole.
If there already is such a hole in the haystack, an Ohel already exists for the entire area of the Sukah.
It is then permitted to extend the height of the walls from one Tefach to ten.
This ruling is supported by being the resolution to a contradiction between our Mishnah and a Beraisa.
One Beraisa permits a Sukah cut from within a haystack, while our Mishnah forbids it.
The resolution is the ruling of R. Huna, and the Beraisa speaks of a case where a one-Tefach hole already exists.
Others learn the ruling of R. Huna as having been taught in order to resolve this contradiction (and not having the contradiction being brought as a support to his prior ruling).
MISHNAH: SPACE AT THE BOTTOM OR TOP OF THE WALLS
(Tana Kama): A wall of a Sukah which is woven from the top down is Kosher only if it reaches to within at least three Tefachim from the ground (Lavud).
A wall which begins from the ground is Kosher as long as it reaches a height of ten Tefachim, even though it does not reach within three Tefachim of the Sechach.
(R. Yosi): A wall which is woven from the Sechach down, for at least 10 Tefachim, is Kosher, even if it ends more than three Tefachim from the ground, just like a wall built from the bottom up.
Question: What is the basis for the Machlokes in the Mishnah?
Answer: Whether a Mechitzah Teluyah (more than three Tefachim off the ground) is considered a Mechitzah to permit carrying (R. Yosi) or not (Tana Kama).
The issue is the subject of the Mishnah in Eiruvin:
(Tana Kama): The residents of adjoining courtyards may draw water from a shared well, provided they made a partition for this purpose (not relying on the property divider).
The partition must be 10 Tefachim tall.
It may extend down to the water or only into the lip of the well, as long as it is built inside the well.
(R. Shimon b. Gamliel): The matter is subject to a Machlokes Beis Hillel and Beis Shamai.
The opinion of the Tana Kama is that of Beis Shamai while according to Beis Hillel, the wall must extend close to the level of the water.
Tosfos DH Beis Shamai reverses the opinions of Beis Shamai and Beis Hillel.
(R. Yehudah): The wall of the courtyard may fill that role.
(Rabah bar bar Chanah citing R. Yochanan): R. Yehudah above holds like R. Yosi in our Mishnah (who permits a suspended Mechitzah).
In fact though, R. Yehudah does not hold like R. Yosi, nor does R. Yosi hold like R. Yehudah.
R. Yehudah may only apply his lenient ruling by Eruv (d'Rabanan, from one Reshus ha'Yachid to another), but not by Sukah, which requires a Mechitzah d'Oraysa.
R. Yosi may permit a Mechitzah Teluyah only by Sukah (a Mitzvas Aseh) while R. Yehudah permits it even by Shabbos (largely a Chiyuv Sekilah).
Question: But if R. Yosi concedes that a Mechitzah Teluyah does not work on Shabbos, then on what basis did they permit the incident in his town, Tzipori!?
Answer: That was in the days of R. Yishmael, the son of R. Yosi, who disagreed with his father in this point.
Question: What was that incident?
Answer: They constructed a make-shift Mavoy with sheets hanging from the posts to transport the Sefer Torah for use on Shabbos.
Question: How could they have brought out the sheets without an Eruv!?
Answer: They found sheets hanging, which did not reach the ground, and they permitted their use, even though they were a Mechitzah Teluyah.
AN APPLICATION OF MECHITZAH TELUYAH
R. Chisda permits putting up a mat in between the ceiling and the floor to form the wall of a Sukah.
The smallest height for the mat (in a minimum height Sukah) would be four Tefachim and a bit.
We would be applying Lavud both at the top and at the bottom.
Question: But the law of Lavud is well established!?
Answer: We might not have known to apply Lavud twice.
Question: But we see from the Beraisa (which requires that a wall be seven-plus Tefachim) that we do not apply Lavud twice!?
Answer: That Beraisa is speaking about a large Sukah, taller than ten Tefachim where he hangs the seven-plus Tefachim within three Tefachim of the Sechach (Lavud).
Question: Then what is the news of the Beraisa?
Answer: The Mechitzah is allowed to hang down to within any distance from the bottom (Mechitzah Teluyah is permitted in a Sukah, like R. Yosi).
MINIMUM LENGTH OF A SUKAH
(R. Ami): It is permitted to place a mat or beam of four-plus Tefachim within three Tefachim of an existing wall (and adjacent to it), to form the second wall of the Sukah.
Question: What is the news of this teaching (since Lavud is well established)?
Answer: That the minimum size of a Sukah is seven Tefachim (by seven Tefachim).