כֵּיצַד מְעַבְּרִין אֶת הֶעָרִים, בַּיִת נִכְנָס בַּיִת יוֹצֵא, פָּגוּם נִכְנָס פָּגוּם יוֹצֵא. הָיוּ שָׁם גְּדוּדִיּוֹת גְּבוֹהוֹת עֲשָׂרָה טְפָחִים, וּגְשָׁרִים וּנְפָשׁוֹת, שֶׁיֵּשׁ בָּהֶן בֵּית דִּירָה, מוֹצִיאִין אֶת הַמִּדָּה כְנֶגְדָּן, וְעוֹשִׂין אוֹתָהּ כְּמִין טַבְלָא מְרֻבַּעַת, כְּדֵי שֶׁיְּהֵא נִשְׂכָּר אֶת הַזָּוִיּוֹת: How does one extend the boundaries of cities in order to ensure that all its protrusions are included within the borders of the city? He extends a straight line across the edge of the city, and if a house is recessed and another house protrudes, or a turret [pagum] is recessed and another turret protrudes from that line, and similarly, if there were remnants of walls ten handbreadths high, and bridges and monuments over graves in which there is a residence, one extends the measure of that side of the city as though there were other structures opposite them in the adjacent corner of the city. And prior to measuring the Shabbat limit, one renders the city like a square tablet so that it gains the corners, although there are actually no houses in those corners.
נוֹתְנִין קַרְפֵּף לָעִיר, דִּבְרֵי רַבִּי מֵאִיר. וַחֲכָמִים אוֹמְרִים, לֹא אָמְרוּ קַרְפֵּף אֶלָּא בֵין שְׁתֵּי עֲיָרוֹת, אִם יֵשׁ לָזוֹ שִׁבְעִים אַמָּה וְשִׁירַיִם, וְלָזוֹ שִׁבְעִים אַמָּה וְשִׁירַיִם, עוֹשֶׂה קַרְפֵּף לִשְׁתֵּיהֶן לִהְיוֹתָן כְּאֶחָת: One allocates a karpef to every city, i.e., the measure of a karpef, which is slightly more than seventy cubits, is added to every city, and the two thousand cubits of the Shabbat limit are measured from there; this is the statement of Rabbi Meir. And the Rabbis say: They spoke of the addition of a karpef only with regard to the space between two adjacent cities. How so? If this city has seventy cubits and a remainder vacant on one side, and that city has seventy cubits and a remainder vacant on the adjacent side, and the two areas of seventy-plus cubits overlap, the karpef combines the two cities into one.
וְכֵן שְׁלֹשָׁה כְפָרִים הַמְּשֻׁלָּשִׁין, אִם יֵשׁ בֵּין שְׁנַיִם הַחִיצוֹנִים מֵאָה וְאַרְבָּעִים וְאֶחָד וּשְׁלִישׁ, עָשָׂה אֶמְצָעִי אֶת שְׁלָשְׁתָּן לִהְיוֹתָן כְּאֶחָד: And likewise, in the case of three villages that are arranged as a triangle, if there are only 141⅓ cubits separating between the two outer villages, the middle village combines the three villages into one.
אֵין מוֹדְדִין אֶלָּא בְחֶבֶל שֶׁל חֲמִשִּׁים אַמָּה, לֹא פָחוֹת וְלֹא יוֹתֵר. וְלֹא יִמְדּוֹד אֶלָּא כְנֶגֶד לִבּוֹ. הָיָה מוֹדֵד וְהִגִּיעַ לְגַיְא אוֹ לְגָדֵר, מַבְלִיעוֹ וְחוֹזֵר לְמִדָּתוֹ. הִגִּיעַ לְהָר, מַבְלִיעוֹ וְחוֹזֵר לְמִדָּתוֹ, וּבִלְבַד שֶׁלֹּא יֵצֵא חוּץ לַתְּחוּם. אִם אֵינוֹ יָכוֹל לְהַבְלִיעוֹ, בָּזוֹ אָמַר רַבִּי דוֹסְתַּאי בַּר רַבִּי יַנַּאי מִשּׁוּם רַבִּי מֵאִיר, שָׁמַעְתִּי שֶׁמְּקַדְּרִין בֶּהָרִים: One may measure a Shabbat limit only with a rope fifty cubits long, no less and no more, as will be explained in the Gemara. And one may measure the limit only at the level of one’s heart, i.e., whoever comes to measure the limit must hold the rope next to his chest. If one was measuring the limit and he reached a canyon or a fence, the height of the fence and the depth of the canyon are not counted toward the two thousand cubits; rather, he spans it and then resumes his measurement. Two people hold the two ends of the rope straight across the canyon or the fence, and the distance is measured as though the area were completely flat. If one reached a hill, he does not measure its height; rather, he spans the hill as if it were not there and then resumes his measurement, provided he does not thereby go out beyond the city’s Shabbat limit, as those watching the surveyor might mistakenly think the limit extends to that point. If, due to the width of the canyon or hill, he cannot span it, with regard to this situation Rabbi Dostai bar Yannai said in the name of Rabbi Meir: I heard that one may pierce hills. In other words, one measures the distance as if there were a hole from one side of the hill to the other, so that in effect, he measures only the horizontal distance and ignores the differences in elevation.
אֵין מוֹדְדִין אֶלָּא מִן הַמֻּמְחֶה. רִבָּה לְמָקוֹם אֶחָד וּמִעֵט לְמָקוֹם אַחֵר, שׁוֹמְעִין לִמְקוֹם שֶׁרִבָּה. רִבָּה לְאֶחָד וּמִעֵט לְאַחֵר, שׁוֹמְעִין לַמְרֻבֶּה. אֲפִלּוּ עֶבֶד, אֲפִלּוּ שִׁפְחָה, נֶאֱמָנִין לוֹמַר, עַד כָּאן תְּחוּם שַׁבָּת, שֶׁלֹּא אָמְרוּ חֲכָמִים אֶת הַדָּבָר לְהַחֲמִיר אֶלָּא לְהָקֵל: One may measure the Shabbat limit only with an expert surveyor. If it is discovered that the surveyor extended the limit in one place and reduced it in another place, so that the line marking the Shabbat limit is not straight, one accepts the measurement of the place where he extended the limit and straightens the limit accordingly. Similarly, if the surveyor extended the limit for one and reduced it for another, one accepts the extended measurement. And furthermore, even a gentile slave and even a gentile maidservant, whose testimonies are generally considered unreliable, are trustworthy to say: The Shabbat limit extended until here; as the Sages did not state the matter, the laws of Shabbat limits, to be stringent, but rather to be lenient. The prohibition to walk more than two thousand cubits is rabbinic in origin and is therefore interpreted leniently.
עִיר שֶׁל יָחִיד וְנַעֲשֵׂית שֶׁל רַבִּים, מְעָרְבִין אֶת כֻּלָּהּ. וְשֶׁל רַבִּים וְנַעֲשֵׂית שֶׁל יָחִיד, אֵין מְעָרְבִין אֶת כֻּלָּהּ, אֶלָּא אִם כֵּן עָשָׂה חוּצָה לָהּ כְּעִיר חֲדָשָׁה שֶׁבִּיהוּדָה, שֶׁיֵּשׁ בָּהּ חֲמִשִּׁים דִּיוּרִים, דִּבְרֵי רַבִּי יְהוּדָה. רַבִּי שִׁמְעוֹן אוֹמֵר, שָׁלֹשׁ חֲצֵרוֹת שֶׁל שְׁנֵי בָתִּים: Although this chapter as a whole deals with halakhot governing the joining of Shabbat boundaries, this mishna returns to the halakhot governing a joining of courtyards. If a private city, which does not have many residents, grows and becomes a heavily populated public city, one may establish a joining of the courtyards for all of it, as long as it does not include a public domain as defined by Torah law. And if a public city loses residents over time and becomes a private city, one may not establish an eiruv for all of it unless one maintains an area outside the eiruv that is like the size of the city of Ḥadasha in Judea, which has fifty residents. Carrying within the eiruv is permitted, but it remains prohibited to carry in the area excluded from the eiruv. The reason for this requirement is to ensure that the laws of eiruv will not be forgotten. This is the statement of Rabbi Yehuda. Rabbi Shimon says: The excluded area need not be so large; rather, it is sufficient to exclude three courtyards with two houses each.
מִי שֶׁהָיָה בַמִּזְרָח וְאָמַר לִבְנוֹ, עָרֵב לִי בַמַּעֲרָב, בַּמַּעֲרָב וְאָמַר לִבְנוֹ, עָרֵב לִי בַמִּזְרָח, אִם יֵשׁ הֵימֶנּוּ וּלְבֵיתוֹ אַלְפַּיִם אַמּוֹת, וּלְעֵרוּבוֹ יוֹתֵר מִכָּאן, מֻתָּר לְבֵיתוֹ וְאָסוּר לְעֵרוּבוֹ. לְעֵרוּבוֹ אַלְפַּיִם אַמָּה, וּלְבֵיתוֹ יוֹתֵר מִכָּאן, אָסוּר לְבֵיתוֹ וּמֻתָּר לְעֵרוּבוֹ. הַנּוֹתֵן אֶת עֵרוּבוֹ בְעִבּוּרָהּ שֶׁל עִיר, לֹא עָשָׂה וְלֹא כְלוּם. נְתָנוֹ חוּץ לַתְּחוּם, אֲפִלּוּ אַמָּה אַחַת, מַה שֶׁנִּשְׂכָּר הוּא מַפְסִיד: One who was to the east of his home when Shabbat began, and he had said to his son before Shabbat: Establish an eiruv for me to the west; or, if he was to the west of his home and he had said to his son: Establish an eiruv for me to the east, the halakha is as follows: If there is a distance of two thousand cubits from his current location to his house, and the distance to his eiruv is greater than this, he is permitted to walk to his house, and from there he may walk two thousand cubits in every direction, but it is prohibited for him to walk to the spot where his son had deposited his eiruv. If the distance from one’s current location to his eiruv is two thousand cubits, and the distance to his house is greater than this, he is prohibited from walking to his house, and he is permitted to walk to the spot of his eiruv, and from there he may walk two thousand cubits in every direction. In other words, with regard to the Shabbat limit, one’s place of residence for Shabbat cannot be more than two thousand cubits from his physical location when Shabbat begins. One who places his eiruv in the outskirts of the city, i.e., within an area of slightly more than seventy cubits surrounding the city, it is as though he has not done anything. The two thousand cubits of one’s Shabbat limit are measured from the edge of the outskirts of the city even if there is no eiruv, and one therefore gains nothing from placing an eiruv within this area. If, however, he placed his eiruv outside the city’s boundary, even if he placed it only one cubit beyond the city, what he gains in distance through his eiruv on one side of the city he loses on the other side.
אַנְשֵׁי עִיר גְּדוֹלָה מְהַלְּכִין אֶת כָּל עִיר קְטַנָּה, וְאֵין אַנְשֵׁי עִיר קְטַנָּה מְהַלְּכִין אֶת כָּל עִיר גְּדוֹלָה. כֵּיצַד. מִי שֶׁהָיָה בְעִיר גְּדוֹלָה וְנָתַן אֶת עֵרוּבוֹ בְעִיר קְטַנָּה, בְּעִיר קְטַנָּה וְנָתַן אֶת עֵרוּבוֹ בְעִיר גְּדוֹלָה, מְהַלֵּךְ אֶת כֻּלָּהּ וְחוּצָה לָהּ אַלְפַּיִם אַמָּה. וְרַבִּי עֲקִיבָא אוֹמֵר, אֵין לוֹ אֶלָּא מִמְּקוֹם עֵרוּבוֹ אַלְפַּיִם אַמָּה: The residents of a large city may walk through an entire small city, and the residents of a small city may not walk through an entire large city, even if part of it is located more than two thousand cubits from their city. How so? One who was in a large city and placed his eiruv in a small city, or one who was in a small city and placed his eiruv in a large city, may walk through the entire city in which he placed his eiruv and another two thousand cubits beyond it, as the entire city is considered as though it were only four cubits. Rabbi Akiva says: He has only two thousand cubits from the place of his eiruv, as the actual area of the city is included in the calculation.
אָמַר לָהֶן רַבִּי עֲקִיבָא, אִי אַתֶּם מוֹדִים לִי בְנוֹתֵן עֵרוּבוֹ בִמְעָרָה, שֶׁאֵין לוֹ מִמְּקוֹם עֵרוּבוֹ אֶלָּא אַלְפַּיִם אַמָּה. אָמְרוּ לוֹ, אֵימָתַי, בִּזְמַן שֶׁאֵין בָּהּ דִּיוּרִין, אֲבָל יֶשׁ בָּהּ דִּיוּרִין, מְהַלֵּךְ אֶת כֻּלָּהּ וְחוּצָה לָהּ אַלְפַּיִם אַמָּה. נִמְצָא, קַל תּוֹכָהּ מֵעַל גַּבָּהּ. וְלַמּוֹדֵד שֶׁאָמְרוּ נוֹתְנִין לוֹ אַלְפַּיִם, שֶׁאֲפִלּוּ סוֹף מִדָּתוֹ כָּלֶה בִמְעָרָה: Rabbi Akiva said to the Rabbis: Do you not concede to me that one who places his eiruv in a cave has only two thousand cubits from the place of his eiruv, and that consequently the entire cave is not considered as merely four cubits? The Rabbis said to him: When does this apply? When the cave has no residents. But if it has residents, it is considered as though it were only four cubits, and one may walk through all of it and another two thousand cubits beyond it. Consequently, the halakha with regard to an eiruv placed inside a cave is sometimes more lenient than the halakha governing an eiruv placed in the area above the cave. If one places his eiruv inside a cave that has residents, he has two thousand cubits beyond the cave; if he places it above the cave, where there are no residents, he has only two thousand cubits from the place of his eiruv. And as for one who is measuring his Shabbat limit, with regard to whom the Sages said that one gives him two thousand cubits, that measurement applies even if the end of his measurement terminates in the middle of a cave. He may not walk further into the cave, even if the cave is inhabited.