Thursday Night Chazara

Dov Ber Polisky -6:20 Pacific/ 8:20 Central/9:20 Eastern
Gabe Fogel -  6:40 Pacific/8:40 Central/9:40 Eastern

Review and Thought Questions

מאן תנא להא דתנו רבנן: בית שאין בו ארבע אמות על ארבע אמות, פטור מן המזוזה ומן המעקה, ואינו מטמא בנגעים, ואינו נחלט בבתי ערי חומה, ואין חוזרין עליו מעורכי המלחמה, ואין מערבין בו ואין משתתפין בו, ואין מניחין בו עירוב, ואין עושין אותו עיבור בין שתי עיירות ואין האחין והשותפין חולקין בו. לימא רבי היא ולא רבנן? - אפילו תימא רבנן. עד כאן לא קאמרי רבנן התם אלא לענין סוכה, דדירת עראי היא. אבל לגבי בית, דדירת קבע הוא - אפילו רבנן מודו, דאי אית ביה ארבע אמות על ארבע אמות - דיירי ביה אינשי, ואי לא - לא דיירי ביה אינשי.

Yesterday, we began the section at the bottom of ג. – in which the Gemara inquires about the authorship of the baraita dealing with a house that is less than 4 x 4 amot –  and all of the exemptions in various scenarios, including

-        from fence around a roof

and from the inapplicability of the structure to the problem of

-        צרעת – halachic leprosy

-        Permission to return from war to dedicate his home – and more.

The Gemara, as we saw, is going to propose that this is authored by Rebbe, and is going to reject this view and argue that it could even be authored by Rabanan.

Thought Questions for tonight:

1)     What view of Rebbe is the Gemara referring to?

2)     What view of Rabanan is the Gemara referring to?

3)     In light of what you answered in #1, why does the Gemara think that the baraita was authored by Rebbe and not Rabanan?

4)     When the Gemara rejects this proposal, what distinction does it make to explain the applicability of the baraita to the view of Rabanan?

Tonight, we are going to do an overview of the Perek from the beginning to map out the structure of what we've been learning for the past several weeks.  See you in shiur!

Chasurei Mechsarah...

Mar Zutrah offers an apparent proof that the two renditions of Chachamim's view represent BS and BH's views respectively - and that the issue of their machloket is the minimal shiur of a succah. The support is noted in the words of the baraita - of "Poslin" and "Machshirin" - literally: disqualify and declare kosher.  If the subject of their machloket was the question of whether or not we make a rabbinic Gezeira, then the terms that should have been used are "fulfilled" (yatzah) and "not fulfilled" (lo yatzah) his obligation.  This seems to prove that the issue is the shiur of the succah.

The baraita in fact gives an indication in both directions.  To review:

1) The fact that the baraita sets up the scenario as a person whose rov and rosh are in the succah and table is in the house implies that the topic is whether, given where he is sitting, he has fulfilled the mitzvah

2) The terms "Poslin" and "machshirin", however, indicate that the topic is whether or not the succah is kosher.

The Gemara resolves this contradiction using a חסורי מחסרא - which means: something is missing in the text of the baraita.  והכי קתני -  and this is how it should read:

The Gemara precedes then to "edit" the baraita in a way that the first entry into the baraita - which talks about the man's physical position - is followed by a disagreement as to whether he is yotzeh (fulfilled) his mitzvah or not yotzeh (not fulfilled) his mitzvah.  The gemara then inserts a new scenario - ie a succah that only holds his rosh and rov [but not table] - BS pasuls and BH says is kosher.

Now we have resolved the contradictory indicators as to what BH and BS are disagreeing about- and thereby reaffirm the original discussion between R. Shmuel and R. Aba as truly representing the view of BS in their argument with BHillel

What are BH and BS arguing about?

The last part of the Gemara (from last Wednesday’s shiur) attempted to reinforce the מתקיף לה by showing from the language of the baraita that the real machloket between BH and BS was a גזירה and not the definition of the minimal shiur of a succah.  The proof was from the fact that the baraita set up a case of a person who was sitting in the succah and his table was in the house.  If, says the Gemara, the machloket between BH and BS dealt with the shiur of a succah, the baraita should have been discussing a succah that either contains or doesn’t contain enough room for rosho, rubo, and shulchano….From this we sharpen the challenge to R. Shmuel and R. Aba’s view evident early in this sugyah. 

The Gemara attempts to defend the original position by arguing once again that BH and BS are indeed arguing re: shiur of a succah.  It does so by citing two baraitot, both involving a machloket between Chachamim/TK and Rebbe.  In both cases, Rebbe holds that a minimal succah is 4 x 4, but Chachamim seem to change their position between the two sources: in one, they hold rosho, rubo, shulchano, and in the other, just rosho and rubo alone.

The Gemara resolves the contradiction by maintaining that one is a report of the view of BS and one of BH

Review of Last Wednesday Night's Shiur

אמר רב שמואל בר יצחק: הלכה, צריכה שתהא מחזקת ראשו ורובו ושולחנו.

Consistent with the way the Gemara approached the halacha on 2b - in which both R. Huna and R. Chanan were quoted as ruling that the minimal shiur of a succah is Rosho Rubo V'Shulchano - R.Shmuel Bar Yitzchak rules the same.  This is consistent with the view of the Rabanan as opposed to Rebbe .

אמר ליה רבי אבא: כמאן - כבית שמאי? - אמר ליה: אלא כמאן?

R. Abba says to R. Shmuel  - who is this consistent with ? With Bet Shammai.  Rashi explains that B. Hillel does not require the measurement to include the Shulchan.  So although the overall approach seems to be consistent with the Rabanan vs Rebbe camp , R. Abba is troubled by the fact that R. Shmuel seems to be ruling like Beit Shammai as opposed to Beit Hillel. R. Shmuel rhetorically asks him, “Well, who else do you think I’m ruling like?

איכא דאמרי, אמר רבי אבא: דאמר לך מני? אמר ליה: - בית שמאי היא, ולא תזוז מינה.

Another version of the interaction, separated by an איכא דאמרי – there are those render the conversation differently:  R. Aba said instead, ‘who told you that such was the measurement of the succah?” To which the answer came: It’s Beit Shammai’s view (and even so) don’t depart from it.  Ie that’s the halacha!

מתקיף לה רב נחמן בר יצחק: ממאי דבית שמאי ובית הלל בסוכה קטנה פליגי? דלמא בסוכה גדולה פליגי, וכגון דיתיב אפומא דמטולתא, ושולחנו בתוך הבית

.

We noted that a מתקיף is always an attack question, based not on a Baraita or mishna alone, but on a logical point.  The questioner – Rav Nachman Bar Yitzchak – questions the validity of assuming that Beit Shammai and Hillel were arguing over the minimal shiur of a succah.  Perhaps the ruling of R. Shmuel is not controversial at all.  Beit Hillel and Beit Shammai are instead arguing over a case of a large succah, in a case where the person is sitting at the entry to the succah, with his table in the house, or out of the succah.

 דבית שמאי סברי: גזרינן שמא ימשך אחר שולחנו, ובית הלל סברי: לא גזרינן. ודיקא נמי, דקתני: מי שהיה ראשו ורובו בסוכה ושולחנו בתוך הבית, בית שמאי פוסלין ובית הלל מכשירין. ואם איתא מחזקת ואינה מחזקת מיבעי ליה. ובסוכה קטנה לא פליגי? 

In this approach, Beit Shammai issues a decree that a person cannot fulfill his mitzvah in this way, because he may be drawn after his table; Beit Hillel does not make such a decree.  In other words, the table/no table concern doesn’t relate to whether the minimal shiur of a succah includes the area of a table, BS requiring it and BH not requiring it – but whether there should be a gezeira of non-fulfilment of the mitzvah because of such a decree.

The Gemara then cites the wording of the machloket BH and BS.  We will review this at the start of Sunday night’s shiur – but it basically focuses on the choice of words of the baraita – the case of which seems to be in a large succah w/the concern being such a Gezeira.   Were they to be arguing about the minimal size of a succah, the scenarios should have referred to a succah that does contain vs. doesn’t contain a table…

Questions for Wednesday Night

Highlight the Key Expressions that appear in the passage below

Questions:

1. How does Rav Shmuel Bar Yitzchak pasken on the minimal size of a succah?
2. What was R. Aba’s response?
3. How does Rav Shmuel respond to R. Aba’s question?
4. How does the second version of the incident differ from the first?
5. What is a מתקיף לה – ie what does it always indicate in a Gemara?
6. What is R. Nachman Bar Yitzchak’s proposal – and how does it differ from the previous understanding of Beit Shammai and Beit Hillel?
7. What does  דיקא נמי, דקתניalways mean and how is it used here?

אמר רב שמואל בר יצחק: הלכה, צריכה שתהא מחזקת ראשו ורובו ושולחנו. אמר ליה רבי אבא: כמאן - כבית שמאי? - אמר ליה: אלא כמאן? איכא דאמרי, אמר רבי אבא: דאמר לך מני? אמר ליה: - בית שמאי היא, ולא תזוז מינה. מתקיף לה רב נחמן בר יצחק: ממאי דבית שמאי ובית הלל בסוכה קטנה פליגי? דלמא בסוכה גדולה פליגי, וכגון דיתיב אפומא דמטולתא, ושולחנו בתוך הבית. דבית שמאי סברי: גזרינן שמא ימשך אחר שולחנו, ובית הלל סברי: לא גזרינן. ודיקא נמי, דקתני: מי שהיה ראשו ורובו בסוכה ושולחנו בתוך הבית, בית שמאי פוסלין ובית הלל מכשירין. ואם איתא מחזקת ואינה מחזקת מיבעי ליה. ובסוכה קטנה לא פליגי? והתניא: מחזקת ראשו ורובו ושולחנו - כשרה, רבי אומר: עד שיהא בה ארבע אמות על ארבע אמות. ותניא אידך, רבי אומר: כל סוכה שאין בה ארבע אמות על ארבע אמות - פסולה, וחכמים אומרים: אפילו אינה מחזקת אלא ראשו ורובו כשרה, ואילו שולחנו לא קתני. קשיין אהדדי! אלא לאו שמע מינה: הא - בית שמאי, הא בית הלל. אמר מר זוטרא: מתניתין נמי דיקא, מדקתני בית שמאי פוסלין ובית הלל מכשירין, ואם איתא - בית שמאי אומרים לא יצא ובית הלל אומרים יצא מיבעי ליה. - ואלא קשיא מי שהיה! - לעולם בתרתי פליגי; פליגי בסוכה קטנה, ופליגי בסוכה גדולה, וחסורי מיחסרא והכי קתני: מי שהיה ראשו ורובו בסוכה ושולחנו בתוך הבית, בית שמאי אומרים לא יצא, ובית הלל אומרים: יצא. ושאינה מחזקת אלא כדי ראשו ורובו בלבד, בית שמאי פוסלין ובית הלל מכשירין.

Digital Review of Tuesday's Shiur

R. Yoshiya, R. Huna, R. Chanan

More than 20 ama high succah is machloket between TK and RY – three difft views as to when TK would agree with RY that such a succah is kosher

Q1מיתיבי:

סוכה שהיא גבוהה למעלה מעשרים אמה - פסולה, ורבי יהודה מכשיר עד ארבעים וחמשים אמה.

          אמר רבי יהודה: מעשה בהילני המלכה בלוד, שהיתה סוכתה גבוהה מעשרים אמה, והיו זקנים נכנסין ויוצאין לשם, ולא אמרו לה דבר. –

         אמרו לו: משם ראייה? אשה היתה ופטורה מן הסוכה.     

         אמר להן: והלא שבעה בנים הוו לה. ועוד: כל  מעשיה לא עשתה אלא על פי חכמים.

למה לי למיתני ועוד כל מעשיה לא עשתה אלא על פי חכמים? הכי קאמר להו: כי תאמרו בנים קטנים היו, וקטנים פטורין מן הסוכה, כיון דשבעה הוו - אי אפשר דלא הוי בהו חד שאינו צריך לאמו. וכי תימרו: קטן שאינו צריך לאמו - מדרבנן הוא דמיחייב, ואיהי בדרבנן לא משגחה - תא שמע: ועוד כל מעשיה לא עשתה אלא על פי חכמים.

Q1בשלמא למאן דאמר בשאין דפנות מגיעות לסכך מחלוקת - דרכה של מלכה לישב בסוכה שאין דפנות מגיעות לסכך משום אוירא. Works well for R. Yoshiya

אלא, למאן דאמר בסוכה קטנה מחלוקת, וכי דרכה של מלכה לישב בסוכה קטנה?Doesn’t work well for R. Huna

]וכי דרכה של מלכה - והלא נערותיה ומשרתיה מסובים עמה! {

  

         -   A1אמר רבה בר רב אדא: לא נצרכה אלא לסוכה העשויה קיטוניות קיטוניות. -

: Q2          וכי דרכה של מלכה לישב בסוכה העשויה קיטוניות קיטוניות? –

  A2               אמר רב אשי: לא נצרכה אלא לקיטוניות שבה.

רבנן סברי: בניה בסוכה מעליא הוו יתבי, ואיהי יתבה בקיטוניות משום צניעותא, ומשום הכי לא אמרי לה דבר.

ורבי יהודה סבר: בניה גבה הוו יתבי, ואפילו הכי לא אמרי לה דבר.

Chazara Times for Sunday

6:00/8:00/9:00  Gabe Fogel

6:20/8:20/9:20 Frank Stechel

6:40/8:40/9:40  Dov Ber Polisky

Summary of Monday Shiur and Thought Question

תלמוד בבלי מסכת סוכה דף ב עמוד ב

כמאן אזלא הא דאמר רבי יאשיה אמר רב: מחלוקת בשאין דפנות מגיעות לסכך,

R. Yoshiya/Rav: The machloket between Tanna Kamma and R. Yehuda in our mishna is only in a scenario in which the walls don’t reach the סכך – in that scenario, TK says that the succah is פסולה since a person won’t lift his eyes so high – and he will lack the awareness at the time he is sitting there, that he is in a succah commanded by Hashem

 אבל דפנות מגיעות לסכך - אפילו למעלה מעשרים אמה כשרה.

• But when the walls reach the סכך, it’s kosher (even according to TK) if the succah is higher than 20 amot

 כמאן – כרבה, דאמר: משום דלא שלטא בה עינא, וכיון דדפנות מגיעות לסכך – משלט שלטא בה עינא.

• This statement of Rav’s is in accordance with Raba, who said that the problem of the 20 ama high succah is that one’s eyes won’t focus on  סכךthat high…once the walls reach the סכך, a person’s eyes will be aware of the (even very high) schach…

כמאן אזלא הא דאמר רב הונא אמר רב: מחלוקת בשאין בה אלא ארבע אמות על ארבע אמות,.

R. Huna/Rav: The machloket between Tanna Kamma and R. Yehuda in our mishna is only in a scenario in which the succah measures only 4 x 4 amot,

אבל יש בה יותר מארבע אמות על ארבע אמות - אפילו למעלה מעשרים אמה כשרה.

• but if there is more than 4 x 4 amot in the succah, the succah is kosher even if above 20 amot in height

כמאן - כרבי זירא, דאמר: משום צל הוא, וכיון דרויחא - איכא צל סוכה

• This statement of Rav’s is in accordance with R. Zeira, who said that the problem of the 20 ama high succah is that the walls, and not the סכך, are providing the shade.  Once the succah is roomer, then the סכך provides the shade even with a 20 ama high succah

כמאן אזלא הא דאמר רב חנן בר רבה אמר רב: מחלוקת בשאינה מחזקת אלא כדי ראשו ורובו ושולחנו,

Rav Chanan/Rav: The machloket between the Tanna Kamma and R. Yehuda in our mishna is only if the succah only holds his head, the majority of his body and  his table

אבל מחזקת יותר מכדי ראשו ורובו ושולחנו - אפילו למעלה מעשרים אמה כשרה.

But if it holds more than this, then it’s kosher even according to TK if it’s over 20 amot high

כמאן? דלא כחד.

Who is it according to? Not like any one of the Amoraim – and here’s why:

Not like Raba: Since, according to Raba, the problem is that a person’s eyes will not focus on the סכך, in a succah higher than 20 amot, he will not all of a sudden focus on the סכך if the succah is larger than 4 x 4!

Not like R. Zeira: Since, according to R. Zeira, the problem is that the walls and not the סכך is providing the shade, in a succah higher than 20 amot!

Not like Rava: Since, according to Rava, the problem is that such a height requires permanent walls, and the Torah insisted on a height that could support temporary walls, this problem will not be alleviated by a succah that has an area of over 4 x 4

-                                            

The Gemara then makes the following statement:

בשלמא דרבי יאשיה פליגא אדרב הונא ורב חנן בר רבה, דאינהו קא יהבי שעורא במשכא, ואיהו לא קא יהיב שעורא במשכא.

As we mentioned in our shiur on Monday evening, it is clear that there are different citations of Rav’s view at work here.  Whenever a talmid reports a view in the name of his teacher, it is possible that he will have a different understanding of the teacher’s view than another talmid.  This could be for a number of reasons….

The Gemara initially states that it is clear that Rav Yoshiya (view 1) disagrees with the rendition of Rav Huna and Rav Chanan, since their focus is that the area of the succah expanding would prompt the TK to declare the succah kosher.  According to Ritvah, it is clear that he heard a fundamentally different principle from Rav than the other Amoraim.  He didn’t hear a halacha from Rav, and then offer his own interpretation

אלא רב הונא ורב חנן בר רבה, נימא בהכשר סוכה קמיפלגי; דמר סבר: הכשר סוכה בארבע אמות, ומר סבר: הכשר סוכה במחזקת ראשו ורובו ושולחנו?

However, Rav Huna and Rav Chanan (according to Ritvah):It’s possible that they don’t fundamentally disagree as to what their Rebbe said, because they both actually heard Rav say that the disagreement between TK and RY in our mishna takes place when the succah does not have its minimal shiur and they went on subsequently to apply their own specific views as to what the minimal shiur of a succah is Rav Huna: 4 x 4; R. Chanan, head, most of body, table…

I tried to suggest why this step in the Gemara is considered a  קושיא- why this part of the Gemara is phrased as a בשלמא and אלא…

My suggestion the other night was that the Gemara had a hard time believing that these Amoraim would make a statement without attributing their approaches back to the Tanna whom they were quoting… After seeing the Ritvah, however, I would like to suggest the following: What was bothering the Gemara was that R. Huna would be ruling like the lone view of Rebbe, while R. Chanan rules like Rabanan (the majority view).  The Gemara is not pleased with an approach which has R. Huna agreeing with a minority view…

This propels the Gemara to conclude:

- לא, דכולי עלמא הכשר סוכה ראשו ורובו ושולחנו. והכא בהא קמיפלגי; דמר סבר: במחזקת ראשו ורובו ושולחנו פליגי, אבל יותר מראשו ורובו ושולחנו - דברי הכל כשרה. ומר סבר: מראשו ורובו ושולחנו עד ארבע אמות פליגי, אבל יותר מארבע אמות - דברי הכל כשרה.

According to Ritvah: Both Rav Huna and R. Chanan rule like Rabanan (the majority view) that the minimum measurement of a succah is head, most of body etc, and they are each claiming that they heard EXACTLY THAT MEASUREMENT from Rav…not, as we said earlier, that they heard “minimal measurement of Succah” from Rav, and then offered their own interpretation.

In shiur, we can discuss the question: What was gained by the Gemara in approaching the machloket between R. Hunan and Rav Chanan this way?

Reserve Chazara spots now

Gabe Fogel 6 pm Pacific

Thursday shiur review

Review of Thursday’s shiur:

R. Zeira and Rava do not agree with Rava – why? They understand the the ידיעה referred to in the pasuk refers to the lesson that later generations will learn that Hashem protected Am Yisrael with the ענני הכבוד – not (as Raba understands it) as referring to the knowledge that we are sitting in a Succah that Hashem commanded……

Raba and Rava do not agree with R. Zeira – why? The reference to the shade of the Succah is a reference to the Divine Protection that will be provided Am Yisrael in the times of the Mashiach. R. Zeira responds: If that was the ONLY intention of the pasuk in the Navi, the term “Chuppah” would have been used. The use of the term “Succah” conveys both the prophecy PLUS the halachic information that the shade must be provided by the סכך

R. Zeira and Raba do not agree with Rava – for the same reason Abaye objected to Rava’s approach.

The Gemara then goes on to successive quotes of Rav – asking: “according to which of the three approaches on 2a do these statements align?

R. Yoshiya/Rav - The machloket between TK and RY in the mishna is only when the walls don’t reach the schach, because then the human eye does not follow the walls up to the schach, but if the walls reach the schach, even TK agrees with RY.  This goes according to Raba, whose whole concern with the 20 ama high limit is the lack of awareness that one is sitting in a Succah that Hashem commanded.

R. Huna/Rav – the Machloket is when the succah is less than 4 amot x 4 amot, but more than that, even TK agrees with RY.  This goes according to R. Zeira, who says that the concern is that the schach doesn’t provide the shade.  But if it’s a larger succah than 4 x 4, even 20 ama high succahs will have their schach provide the shade.

R. Chanan/Rav – the machloket is only where the succah does not contain his head, the majority of his body and his table, but if it holds more, then even TK says it is kosher…We will review in shiur why this must be so….

Thursday Night Shiur

Last night's class focused on the view of Rava as to why a Succah that is higher than twenty amot is not valid as a Succah.

Rava quotes the verse that says, בסוכות תשבו שבעת ימים - "You should dwell in Sukkot for Seven Days". Rava understands that the intention of the Torah is that you should dwell is "Seven Day" Sukkot.  In other words, make for yourselves Sukkot that will last for seven days.   "Leave your permanent homes and enter into temporary dwellings".  A succah higher than 20 amot requires walls that are permanent, stronger foundations, etc...

Abaye's קושיא on Rava is: If that's the case אלא מעתה - (ie from here, based on your logic) it follows: that if a person places schach on iron walls, it would not be a kosher succah.....(Implicit in Abaye's comments is that it is clear that such a succah is kosher.  How, then, could Rava give us a drasha that implies that such a succah would not be valid?

Rava answers: (according to Rashi's explanation) included in a permanent succah is the minimal standard of a temporary succah. The intent of the Torah was not to invalidate a permanent succah, but to set the parameters for the upper height of a succah.  It has to be a height that would tolerate temporary walls and limited foundations.  Therefore, even if the walls were made of iron, such a succah would be kosher, as long as it the succah was a height that would tolerate temporary walls.

We will start this evening with a review of the first few lines of ב: - ie why each approach does not accept the view of the other Amora....

Rava's Approach

See the approach of Rava and Abaye's response:

תלמוד בבלי מסכת סוכה דף ב עמוד א

ורבא אמר: מהכא +ויקרא כג+ בסכת תשבו שבעת ימים. אמרה תורה: כל שבעת הימים צא מדירת קבע ושב בדירת עראי. עד עשרים אמה - אדם עושה דירתו דירת עראי, למעלה מעשרים אמה - אין אדם עושה דירתו דירת עראי, אלא דירת קבע.

 How does Rava understand the purpose of the mitzvah of succah and what impact does that have on the structure of the succah? How does this help explain why a succah cannot be more than 20 amot high

אמר ליה אביי: אלא מעתה, עשה מחיצות של ברזל וסיכך על גבן - הכי נמי דלא הוי סוכה? - אמר ליה, הכי קאמינא לך: עד עשרים אמה, דאדם עושה דירתו דירת עראי, כי עביד ליה דירת קבע - נמי נפיק. למעלה מעשרים אמה, דאדם עושה דירתו דירת קבע, כי עביד ליה דירת עראי - נמי לא נפיק. 

What would this logically lead to, according to Abaye

How does Rava defend his approach while deflecting Abaye's difficulty

Chazara times - to date

All times Pacific/Central/Eastern

6:00/8:00/9:00     Gabe Fogel
6:40/8:40/9:40     Yaakov Grimaldi
7:20/9:20/10:20   Dov Friedman
7:40/9:40/10:40   Dov Ber Polisky

Summary of Thursday Shiur and Chazara Times

On Thursday evening, we noted the following:

When learning Gemara, both to de-mystify what is happening on the Daf, and as an aid to memorizing the content of the daf, it's important to divide the Gemara up into easy-to-remember segments.  The digital version of our amud, sent to you by email following the shiur, appears below.   
Summary: Our Gemara begins with the citing of a mishna referring to the height of a קורה/beam on a מבוי - with a machloket between Tanna Kamma and R. Yehuda, parallel to the machloket in our mishna.
In Q1, the Gemara raises a concern about the lack of parallelism between the term used by TK in our mishna vs. the new mishna.
The Gemara offers to answers, A1 and A2 - separated by an איבעית אימא
In Q2,  the Gemara links back to the mishna, asking what the source is for the din of 20 amot being the upper limit of the height of a succah.
To this, there are three approaches,

• Raba
• R. Zeira
• Rava

Raba - awareness that Hashem commanded us to dwell in Succot - while we are dwelling in them; unique interpretation of למען ידעו דורותיכם

R. Zeira - essence of the mitzvah is to dwell in the shade of סכך; 

when the walls are 20 amot high, a person is dwelling in the shade of the walls

Rava - (we have not yet explained this approach)

On R. Zeira and Rava's approaches, Abaye raises an objection, to which each of the two Amoraim, respectively, responds.  We explained Abaye's קושיא on R. Zeira: based on the concept that the shade must be provided by the סכך, and if it isn't the succah is invalid, a succah built in a valley - between mountains - should be invalid, since the shade is provided by the mountains and not the סכך.  R. Zeira's response: The two cases differ: in the 20 ama high succah, the succah is itself not a kosher halachic structure, because it's built in a way in which the walls create the shade and not the סכך; in the עשתרות קרנים  succah, the succah itself is inherently kosher, and it is just its circumstance ie location which mitigates the effect of the סכך.  Such a succah is indeed kosher!

תלמוד בבלי מסכת סוכה דף ב עמוד א

text from Bar Ilan Responsa Project

גמרא. תנן התם: מבוי שהוא גבוה מעשרים אמה - ימעט, רבי יהודה אומר: אינו צריך.

1Q מאי שנא גבי סוכה דתני פסולה, ומאי שנא גבי מבוי דתני תקנתא?

A1- סוכה דאורייתא - תני פסולה, מבוי דרבנן - תני תקנתא.

 A2  ואיבעית אימא: בדאורייתא נמי תני תקנתא. מיהו, סוכה (דנפישי מילתה) +מסורת הש"ס: [דנפישין מיליה]+ - פסיק ותני פסולה, מבוי דלא נפיש מיליה - תני תקנתא

: Q2מנא הני מילי?

אמר רבה: דאמר קרא +ויקרא כג+ למען ידעו דרתיכם כי בסכות הושבתי את בני ישראל, עד עשרים אמה - אדם יודע שהוא דר בסוכה, למעלה מעשרים אמה - אין אדם יודע שדר בסוכה, משום דלא שלטא בה עינא.

רבי זירא אמר: מהכא +ישעיהו ד+ וסכה תהיה לצל יומם מחרב, עד עשרים אמה - אדם יושב בצל סוכה, למעלה מעשרים אמה - אין אדם יושב בצל סוכה, אלא בצל דפנות. אמר ליה אביי: אלא מעתה, העושה סוכתו בעשתרות קרנים, הכי נמי דלא הוי סוכה? - אמר ליה: התם, דל עשתרות קרנים - איכא צל סוכה, הכא דל דפנות - ליכא צל סוכה.

ורבא אמר: מהכא +ויקרא כג+ בסכת תשבו שבעת ימים. אמרה תורה: כל שבעת הימים צא מדירת קבע ושב בדירת עראי. עד עשרים אמה - אדם עושה דירתו דירת עראי, למעלה מעשרים אמה - אין אדם עושה דירתו דירת עראי, אלא דירת קבע. אמר ליה אביי: אלא מעתה, עשה מחיצות של ברזל וסיכך על גבן - הכי נמי דלא הוי סוכה? - אמר ליה, הכי קאמינא לך: עד עשרים אמה, דאדם עושה דירתו דירת עראי, כי עביד ליה דירת קבע - נמי נפיק. למעלה מעשרים אמה, דאדם עושה דירתו דירת קבע, כי עביד ליה דירת עראי - נמי לא נפיק.

Succah vs. Mavui - Approach #2

In its second answer, denoted by the איבעית אימא - the Gemara says that בדאורייתא נמי תני תקנתא - which we explained to mean: in an area of Torah law, the mishna could have also used a terminology of תקנתא - like ימעט was used in mavui.  In other words, contrary to what the Gemara presumed before, the mishna - whether dealing with a Torah law or a rabbinic law - is indeed an instruction manual; its style would not be impacted by the fact that it was relating to a concept/law that precedes the time of the mishna.

The reason, however, that the mishna did not use a lashon of תקנתא, is that נפישי מילתא - there were many topics being dealt with in the mishna of Succah, whereas only one issue was at stake in the mishna of mavui.  Rashi explains that the language in our mishna would have been rather cumbersome, because each particular problem in our mishna, would have had to have its own separate "instruction" as to what to do.  The word פסולה, however, is broad, relating to the invalid status of a succah that had any one of the psulim mentioned there. Rashi goes on to say that the reason this would be objectionable is the principle of לעולם ילמד אדם את תלמידיו בלשון קצרה - one should always try to be concise when teaching.  The mishna  - at the end of the day - has more of a pedagogical than instructional goal. 

Succah vs. Mavui - Approach #1

Last night's shiur contained a review of the first shiur, emphasizing the parallelism between our mishna and the mishna of מבוי.  In both mishnayot, there is a machloket between Tanna Kamma nd R. Yehuda, and in both, the former is is strict and the latter is lenient. But in the former, Tanna Kamma says that the Succah is pasul while in the case of מבוי, the מבוי must be lowered (namely: the beam, joining the extremities of the open wall, must be lowered)

Why, asks the Gemara, is the concept of "takantah"/fixing used by TK in מבוי ?

A1: Succah is d'oraita, while מבוי is d'rabanan

Now what does this mean?  In other words, how does saying Succah is d'oraita explain the terminology "psula" while saying that מבוי is d'rabanan explain why the term ימעט is used?

(we ruled out the idea that there was some sort of inherent distinction - ie that you COULDN'T lower a very high Succah...so it must be that the terminology of psula was more appropriate by Succah, and the term ימעט was more appropriate by מבוי)

Rashi, in a cryptic message, says earlier that the shiurim of Succah were conveyed prior to the mishna being written.  This Rashi is key to understanding the later Rashis, where he says that re: Succah, the term psula was used to convey that "this succah was not made in accordance with Torah and Halacha" while, later, Rashi says in מבוי - that this is תחילת הוראתו - this is the first time  מבוי has been taught.

We explained it this way: However the halacha is derived from the Torah, the d'oraita exists before the Rabanan came and wrote down the mishna.  There is a concept of a halachic Succah, m'doraita, that preceded the Rabanan.  Regarding d'oraita halachot, it is appropriate to present the case of a Succah that does not measure up to the standard that the Torah has set for a halachic Succah.  Hence פסולה - the 20 ama high succah doesn't make the grade!

With a din d'rabanan, however, the rabbis themselves are the ones that are initiating the new halacha of a beam on a מבוי, (all of מבוי's dinim are d'rabanan!).  Re: this topic, the mishna should function as an instruction manual, to tell us how to apply/use the dinim that the rabbis are מחדש.  It's a pragmatic guide to fulfilling the dinim d'rabanan.    Therefore, the term פסולה is not used, but rather ימעט - lower the מבוי so that it is halachically functional.....