מִשּׁוּם שִׁיעוּרָא וְלָאו שִׁיעוּרָא הוּא, הַאי – לָאו שִׁיעוּרָא הוּא כֵּיוָן דְּלָא שָׁווּ שִׁיעוּרַיְיהוּ לַהֲדָדֵי – לָא מִצְטָרְפִי.

the status of the sukka is determined on the basis of whether it is the requisite measure or it is not the requisite measure. In other words, the difference between unfit roofing that is four cubits and unfit roofing that is less is a unique halakha , completely unrelated to the principle of curved wall. Similarly, it is a unique halakha that three handbreadths of space in a roof render a sukka unfit. In this case, there is not the requisite measure according to either halakha ; and since their measures are not equal to each other, they do not combine to render the sukka unfit. The sukka is rendered unfit only when the measure of unfit roofing reaches four cubits.

אֶלָא לְדִידְכוּ, דְּאָמְרִיתוּ שִׁיעוּר מִשּׁוּם הַפְלָגָה – מַה לִּי אִיתְפַּלַּג בִּסְכָךְ פָּסוּל, מַה לִּי אִתְפַּלַּג בִּסְכָךְ פָּסוּל וַאֲוִיר!

However, according to you, who say that the measure of four handbreadths for unfit roofing is due to the distance between the wall and the fit roofing, which renders the sukka unfit, what is the difference to me if it was distanced due to unfit roofing, and what is the difference to me if it was distanced due to a combination of unfit roofing and space? In either case, the distance between the roofing and the wall should prevent connecting the roofing to the wall. This concludes Rabba’s account of his exchange with the Sages of the school of Rav.

אֲמַר לֵיהּ אַבַּיֵי: וּלְמָר נַמִי, נְהִי דְּלָא שָׁווּ שִׁיעוּרַיְיהוּ בְּסוּכָּה גְּדוֹלָה – בְּסוּכָּה קְטַנָּה מִי לֹא שָׁווּ שִׁיעוּרַיְיהוּ?!

Abaye said to Rabba: And according to the Master, too, although their measures are not equal in a large sukka , which is larger than four cubits, in a small sukka aren’t their measures equal? In a minimally sized sukka , seven by seven handbreadths, three handbreadths of unfit roofing must render the sukka unfit. If the measure of fitness were to remain up to four handbreadths, that would mean that a sukka with a majority of unfit roofing is fit, which is unreasonable. Therefore, Rabba’s contention that the measures of unfit roofing and space are totally different is not precise.

אָמַר לֵיהּ: הָתָם לָאו מִשּׁוּם דְּשָׁווּ שִׁיעוּרַיְיהוּ לַהֲדָדֵי הוּא, אֶלָּא מִשּׁוּם דְּלֵיתֵיהּ לְשִׁיעוּרָא דְּסוּכָּה הוּא.

Rabba said to him: There, in the case of the minimally-sized sukka , the fact that the sukka is unfit is not due to the fact that their measures are equal. Rather, it is due to the fact that in a case where the unfit roofing is three handbreadths, the sukka lacks the minimum required measure of fit roofing. In other words, it is not the amount of unfit roofing that creates the problem; rather, it is that the fit area of the sukka is too small.

וְכָל הֵיכָא דְּלָא שָׁווּ שִׁיעוּרַיְיהוּ לַהֲדָדֵי לָא מִצְטָרְפִי? וְהָתְנַן: הַבֶּגֶד שְׁלֹשָׁה עַל שְׁלֹשָׁה, הַשַּׂק אַרְבָּעָה עַל אַרְבָּעָה, הָעוֹר חֲמִשָּׁה עַל חֲמִשָּׁה, מַפָּץ שִׁשָּׁה עַל שִׁשָּׁה.

Rabba maintains that since the two requisite measures of unfitness are not equal, they do not join together. The Gemara asks: And anywhere that their measures are not equal, do they not combine to constitute the requisite measure? But didn’t we learn in the mishna: The garment must be at least three by three handbreadths zav ; and the sackcloth made from goats’ hair must be at least four by four handbreadths; and the animal hide must be five by five; and a mat must be six by six?

וְתָנֵי עֲלָהּ: הַבֶּגֶד וְהַשַּׂק, הַשַּׂק וְהָעוֹר, הָעוֹר וְהַמַפָּץ – מִצְטָרְפִין זֶה עִם זֶה!

And a baraita is taught concerning the mishna: The garment and the sackcloth, the sackcloth and the hide, and the hide and the mat join together with one another. If one attaches a piece of material that has a smaller, more stringent measure for ritual impurity to a piece of material that has a larger, more lenient measure, the combined cloth is susceptible to contract ritual impurity if together they compose the larger measure. Apparently, two items whose measures are not equal combine to compose the more lenient measure.

הָתָם כִּדְקָתָנֵי טַעְמָא, אָמַר רַבִּי שִׁמְעוֹן: מַה טַּעַם – הוֹאִיל וְרָאוּי לְטַמֵּא מוֹשָׁב, כְּדִתְנַן: הַמְקַצֵּעַ מִכּוּלָּן טֶפַח עַל טֶפַח – טָמֵא.

The Gemara rejects this. There, it is as the reason is taught that Rabbi Shimon said: What is the reason that these different fabrics combine? They combine since all the component materials are fit to become ritually impure through the ritual impurity imparted to a seat upon which a zav sits, halakhot of ritual impurity. As we learned in a mishna: In the case of one who trims and processes a piece of any of the above-mentioned materials handbreadth by one handbreadth, that piece is capable of becoming ritually impure. There is a certain halakha for which each of the different materials has the same measure; they therefore join together in other areas as well.

טֶפַח עַל טֶפַח לְמַאי חֲזִי? וְאָמַר רַבִּי שִׁמְעוֹן בֶּן לָקִישׁ מִשּׁוּם רַבִּי יַנַּאי: הוֹאִיל וְרָאוּי (לִיטְּלוֹ) עַל גַּבֵּי הַחֲמוֹר.

The Gemara asks: For what use is a cloth that is one handbreadth by one handbreadth fit? After all, a rag that has no use does not contract ritual impurity. Rabbi Shimon ben Lakish said in the name of Rabbi Yannai: Since it is suitable for use as a patch on a donkey’s saddlecloth, it is capable of contracting ritual impurity. This ends the discussion of the exchange between Rabba and the Sages of the school of Rav.

בְּסוּרָא אָמְרִי לְהָא שְׁמַעֲתָא בְּהַאי לִישָּׁנָא. בִּנְהַרְדְּעָא מַתְנוּ, אָמַר רַב יְהוּדָה אָמַר שְׁמוּאֵל: סְכָךְ פָּסוּל, בָּאֶמְצַע – פּוֹסֵל בְּאַרְבָּעָה, מִן הַצַּד – פּוֹסֵל בְּאַרְבַּע אַמּוֹת. וְרַב אָמַר: בֵּין מִן הַצַּד בֵּין בָּאֶמְצַע בְּאַרְבַּע אַמּוֹת.

The Gemara notes: In Sura, they stated this halakha in that language cited above. In Neharde’a, however, they taught it as follows: Rav Yehuda said that Shmuel said: Unfit roofing in the center of the sukka renders the sukka unfit with a measure of four handbreadths of unfit roofing. Along the side of the sukka , it renders the sukka unfit with a measure of four cubits of unfit roofing. And Rav said: Both along the side and in the center, it renders the sukka unfit with a measure of four cubits of unfit roofing.

תְּנַן: נָתַן עָלֶיהָ נֶסֶר שֶׁהוּא רָחָב אַרְבָּעָה טְפָחִים – כְּשֵׁרָה. בִּשְׁלָמָא לְרַב, דְּאָמַר בֵּין בָּאֶמְצַע בֵּין מִן הַצַּד בְּאַרְבַּע אַמּוֹת – מִשּׁוּם הָכִי כְּשֵׁרָה. אֶלָא שְׁמוּאֵל, דְּאָמַר בָּאֶמְצַע בְּאַרְבָּעָה, אַמַּאי כְּשֵׁרָה? הָכָא בְּמַאי עָסְקִינַן, מִן הַצַּד.

We learned in a mishna: If one placed a board that is four handbreadths wide atop the sukka , the sukka is fit. And the Gemara asks: Granted, according to Rav, who said that both along the side and in the center, a sukka is rendered unfit with a measure of four cubits of unfit roofing, it is due to that reason that the sukka is fit. However, according to Shmuel, who said that in the center of the sukka , the sukka is rendered unfit with a measure of four handbreadths of unfit roofing, why is the sukka fit? The Gemara answers: With what are we dealing here? It is with a case where he placed the beam along the side; but had he placed it in the center, then according to Shmuel the sukka would indeed be unfit.

תָּא שְׁמַע: שְׁנֵי סְדִינִין – מִצְטָרְפִין, שְׁנֵי נְסָרִים – אֵין מִצְטָרְפִין. רַבִּי מֵאִיר אוֹמֵר: נְסָרִים כִּסְדִינִין.

The Gemara cites a proof with regard to Rav’s opinion. Come and hear: Two sheets placed over the roofing of the sukka join together to render the sukka unfit. However, two boards placed on the sukka do not combine to render the sukka unfit. Rabbi Meir says: Even boards have the same legal status as sheets, and they combine to render the sukka unfit.

בִּשְׁלָמָא לְהָךְ לִישָּׁנָא דְּאָמַר רַב בֵּין בָּאֶמְצַע בֵּין מִן הַצַּד בְּאַרְבַּע אַמּוֹת, מַאי ״מִצְטָרְפִין״ – מִצְטָרְפִין לְאַרְבַּע אַמּוֹת. אֶלָּא לְהַךְ לִישָּׁנָא דְּאָמַר רַב בָּאֶמְצַע בְּאַרְבָּעָה, הֵיכִי דָּמֵי? אִי דְּאִית בְּהוּ אַרְבָּעָה – לָמָּה לְהוּ אִצְטַרוּפִי? אִי דְּלֵית בְּהוּ אַרְבָּעָה – קַנְיָא בְּעָלְמָא נִינְהוּ!

The Gemara clarifies: Granted, according to that version from Neharde’a that Rav said: Both along the side and in the center, a sukka is rendered unfit with a measure of four cubits of unfit roofing, what is the meaning of join together? It means that the two unfit objects join together to comprise four cubits. However, according to this version from Sura, in which Rav said: A sukka is rendered unfit with a measure of four handbreadths of unfit roofing in the center, what are the circumstances? If each of the boards has four handbreadths in its width, why must they join together to render the sukka unfit? If each board is four handbreadths wide, each is capable of rendering the sukka unfit on its own, and if each of the boards does not have four handbreadths in its width, why would Rabbi Meir prohibit their use; they are merely reeds?

לְעוֹלָם דְּאִית בְּהוּ אַרְבָּעָה, וּמַאי מִצְטָרְפִין – מִצְטָרְפִין לְאַרְבַּע אַמּוֹת מִן הַצַּד.

The Gemara answers: Actually, it is a case where each of the boards has four handbreadths in its width, and what is the meaning of join together? It means they join together to constitute four cubits along the side. This understanding fits both versions of Rav’s opinion.

תָּא שְׁמַע: סִכְּכָהּ בִּנְסָרִין שֶׁל אֶרֶז שֶׁיֵּשׁ בָּהֶן אַרְבָּעָה – דִּבְרֵי הַכֹּל פְּסוּלָה. אֵין בָּהֶן אַרְבָּעָה, רַבִּי מֵאִיר פּוֹסֵל, וְרַבִּי יְהוּדָה מַכְשִׁיר.

Come and hear proof from another baraita : If one roofed the entire sukka with cedar beams that have four handbreadths in their width, everyone agrees that the sukka is unfit. If they do not have four handbreadths in their width, Rabbi Meir deems the sukka unfit and Rabbi Yehuda deems it fit.