Question: How can this be effective with regard to Sukah - seing as a third of a Tefach is not visible from inside the Sukah

Refuted Answer: If it is on account of a 'Migu' (See above, 7a) ...

Refutation #1: Firstly, did Rav Kahana build a Sukah only for Shabbos?

Refutation #2: And secondly, that we do not apply 'Migu' min ha'Torah to make up the third wall, as Tosfos explained earlier (7b DH 'Sikach').

Explanation: Rashi explains that this is because the middle wall was n ot made for that purpose.

Question: We learn from our Mishnah that it is Kasher, since it states there 'And similarly a Chatzer that is surrounded by an Achsadrah is Kasher provided there is not four Amos between the wall and the S'chach.

Question (cont.): In spite of the fact that the walls of the house are not made to serve the outside, as the Gemara explained above (Daf 17a).

Explanation #2: It therefore seems that it refers to the canes that protrude behind the Sukah.

Proof: In fact, there are Sefarim that specifically have the text 'One may have thought that these canes were made for the inside and not for the outside' ...

Proof (cont.): And therefore, it ought to be Pasul, seeing as it is not made in order to provide shade; It therefore teaches us that it is Kasher'.

Explanation #1: It is obviously Kasher, seeing as even air, which is more stringent than it (S'chach Pasul) is not Pasul with this Shi'ur?

Explanation #1 (cont.): Rebbi Aba said to him that that is why it adds that 'It has the Din of a Sukah', to teach us that one may sleep underneath it

Explanation (concl.): Because, as far as air less than three Tefachim is concerned, granted it combines to complete the Shi'ur Sukah, one may not sleep underneath it (Rashi).

Question #1: Why did Rebbi Oshaya then mention 'a small Sukah', Seeing as it is equally necessary to teach us that one may sleep under it in a large Sukah?

Refuted Answer: And it is a Dochek to say that he mentions a small 'Sukah' to teach in order to teach us two things - that it combines and that one may sleep underneath it.

Question #2: Furthermore, we always consider less than three Tefachim (of space) as if it was closed - via 'L'vud'?

Refuted Answer: And it cannot be compared to less than three Tefachim of Pasul S'chach ...

Refutation: Since it is not feasible to consider it closed with Kasher S'chach, since it is filled with Pasul S'chach.

Question #3: Moreove, what can one possibly do in a Sukah that is full of holes, whose shade is only fraction more than its sun, to avoid sleeping under the holes?

Explanation #2: It therefore seems like the Sefarim that have the text 'Air combines and one may sleep underneath it, whereas this (Pasul S'chach) combines and one may not sleep underneath it' ...

Explanation #2 (cont.): In other words - When the Gemara asks that 'It is obviously Kasher, since even air that is more stringent that it is not Pasul with this Shi'ur' - to the contrary, S'chach Pasul is the more stringent of the two, since one may not sleep underneath it, and we would have therefore thought that it does not combine either? ...

Precedent: As the Gemara will ask shortly 'Is there anything ... ?'

Question: This is difficult however, from the case where one made the S'chach with spitrods, which the Gemara (above on 15a) declares Kasher if there is a space between them equivalent to them, and where it is impossible to avoid sleeping under the spitrods?

Explanation #3: One therefore explain that when there is (the Shi'ur of) a Hechsher Sukah not counting the air or the Pasuk S'chach, one is permitted to sleep underneath either of them.

Explanation #3 (cont.): And that explains why it mentions 'A small Sukah'.

Proof for Explanation #1: The Yerushalmi in B'rachos (Perek Sheloshah she'Achlu', Halachah 1) however, implies that the air combines but that one may not sleep underneath it - like Rashi's explanation ...

The Yerushalmi: The Yerushalmi writes - 'We are discussing Sukah and we learn from 'Mud that can be poured out': Because we learned there ' If one distanced the S'chach three Tefachim from the walls, it is Pasul; less than that is Kasher. Is one permitted to sleep underneath it?

The Yerushalmi (cont.): Rebbi Yitzchak ben Elyashiv replied from (soft) mud that can be poured out, which completes the Mikvah, but in which one is nevertheless not permitted to Tovel in it; Here too, it completes the Sukah, but one is not permitted to sleep underneath it.

Explanation #1: Rashi explains - 'As we learned in the Mishnah in Maseches Mikva'os (Perek 7, Mishnah 1) "And these are Ma'alin a Mikvah but do not disqualify it, snow, hail, frost, ice salt and soft mud" ...

Explanation #1 (cont.): And 'Ma'alin' means 'complete (the Shi'ur)', but not on their own'.

Question: What does this prove? Also air is not Kasher on its own, so what does it prove ...

Reason: Seeing as soft mud is fit to Tovel in when it completes the Mikvah, and it cannot be compared to air, underneath which one is not permitted to sleep even when it combines (with the S'chach)?

Explanation #2: One therefore needs to explain that one may not Tovel in soft mud even when it combines.

Proof: And so we learned in the Mishnah (Ibid. Perek 2, Mishnah 10) 'If a Mikvah contains forty Sa'ah of water and mud - Rebbi Eliezer permits Toveling in the water but not in the mud, whereas Rebbi Yehoshua permits it ...

Proof (cont.): To what sort of mud is it referring? To mud on top of which the water is floating; But if the water is on one side, then Rebbi Yehoshua concedes that one may Tovel in the water but not in the mud.

Proof (cont.): And what sort of mud are they talking about? According to Rebbi Meir, it is mud into which a cane descends automatically; according to Rebbi Yehudah - it is a location where the measuring reed cannot remain erect ...

Proof (concl.): Aba Eliezer ben D'lai defines it as a location into which the weights sink, Rebbi Eliezer, as mud that will fall into the narrow mouth of a jar, Rebbi Shimon, as mud that will fall into an opening that is two finger-breadths wide and Rebbi Eliezer b'Rebbi Tzadok, mud that one measures in a K'li that holds a Log (which is used to measure liquids.

Introduction to Question: This poses a Kashya on the Gemara in the second Perek of Zevachim (Daf 22a), where Resh Lakish states that 'Whatever completes a Mikvah, completes the water in the Kiyor. but not a Revi'is'.

Introduction to Question (cont.): And the Gemara asks what he is coming to preclude? If it is to preclude soft mud, how does that speak? If a cow will not bend down and drink from it, it will not even complete the Shi'ur of a Mikvah?'

Question: Now if the mud over which Rebbi Eliezer and Rebbi Yehoshua are arguing is soft mud, on what grounds does the Gemara ignore all the Shi'urim of Rebbi Meir, Rebbi Yehudah, Aba Eliezer and all the other Tana'im in Mikva'os and mention the Shi'ur of 'If a cow will bend down and drink', which is not listed there?

Answer: Perhaps all those Shi'urim hinge upon that one - that one Tana holds that with his Shi'ur a cow will drink and the other Tana, with his Shi'ur.

Refuted Question: Nor can one ask 'Let us see what a cow does?'

Refutation: Since not all cows are the same.

Implied Question: And when the Gemara in Kol ha'Basar (Chulin, Daf 106a & 106b) implies that one may Tovel in water from which an animal can no longer drink' ...

Answer: It is speaking, not where the animals cannot drink it on account of the mud, but because it became too disgusting and smelly for them

Answer (cont.): But there is no mud mixed in itm which explains why it is eligible to Tovel in.

Clarification: It speaks in a case where, after the slope has risen to the height of ten Tefachim, the Sukah is still seven Tefachim wide ...

Reason: Because otherwise, the Rabanan would not declare it Kasher, since a Sukah needs to be ten Tefachim tall and seven Tefachim wide.

Chidush: It may well be that there if, after the slope has risen to the height of ten Tefachim, the Sukah is still seven Tefachim wide, then even underneath the part of the slope that is not ten Tefachim tall is Kasher, seeing that it is seven Tefachim wide ...

Precedent: Similar to 'Pesel' that protrudes from the Sukah, according to Rabah and Rav Yosef above (on Amud Alef), who declare Kasher canes that protrude from the front of the Sukah.

Explanation #1: And he made a vertical building of one Tefach, on which he placed the bottom end of the slope; Similarly, when it says 'He distanced one Tefach from the wall', it speaks where he placed S'chach one Tefach wide beside the wall, on which he placed the end of the upper slope.

Explanation #2: From Rashi's explanation it implies that even if the Tefach that he raised from the ground or distanced from the wall is air, it is Kasher ...

Reason: Because, due to 'L'vud', it is considered as if it is stopped up.

Rashi: Since Rashi says that 'If one distanced the edge that is next to the wall one Tefach from the wall, and it was supported by pegs'.

Support: And this is somewhat implied in the Yerushalmi, which reads 'Rebbi Eliezer concedes to the Chachamim that if it is placed on four stones and is raised from the ground one Tefach, it is Kasher'.

Reason: Because 'Whatever comes out from a tree is not subject to Tum'as Ohalim, except for flax' (See Tosfos Yom-Tov) ...

Source: Since we learn this from the Mishkan, in Perek Bameh Madlikin (Shabbos, Daf 28a & 28b)

Refuted Explanation: This does not mean that the Reisha speaks about one case and the Seifa about the other ...

Authentic Explanation: But the Reisha mentions where he made it for lying on regarding all mats - seeing as there are some mats that are made S'tam for S'chach.

Authentic Explanation cont.): And the Seifa too, mentions where he made it for S'chach by all mats - since there are some mats that are made S'tam for lying on.

Explanation #1: And when the Mishnah mentions 'for S'chach' it refers both to the end of the Tana Kama's statement and to the 'S'tam' in the words of Rebbi Eliezer.

Explanation #1 (cont.): And this is what he means 'If he made it specifically for lying on' , it is subject to Tum'ah and one may not use it for S'chach ...

Explanation #1 (cont.): But if it is possible to say that it was made for S'chach - such as where he did specify (otherwise), one may use it for S'chach and it is not subjet to Tum'ah. So Rashi explains.

Implied Question: And the reason that he pushed to explain that this is why the Tana Kama omitted mention of a small mat is ..

Answer: Because he holds that it is specifically in connection with a large mat that we say that S'tam it is for S'chach, whereas a small one is S'tam for lying on.

Explanation #1 (concl.): And Rebbi Eliezer comes to say that a small mat is equivalent to a large one.

Question: In that case, Rebbi Eliezer is not arguing on the main point of the Tana Kama, only on the inference?

Explanation #2: The explanation would therefore seems to be that Rava is only coming to explain the statement of Rebbi Eliezer, whereas that of the Tana Kama remains as before.

Explanation #2 (cont.): However, 'le'Sikuch' that Rebbi Eliezer mentions, is as Rashi explains it - 'If one is able to say that it is for S'chach, such as by S'tam, it is Tahor and may be used for S'chach'.