Eruvin 53A

וגשרים ונפשות שיש בהן בית דירה ⁠— מוציאין את המדה כנגדן. ועושין אותה כמין טבלא מרובעת, כדי שיהא נשכר את הזויות.

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.

גמ׳ רב ושמואל: חד תני ״מעברין״ וחד תני ״מאברין״.

Talmud: The Talmud cites a dispute with regard to the Mishnah’s terminology. Rav and Shmuel disagreed: One taught that the term in the Mishnah is me’abberin, with the letter ayin, and one taught that the term in the Mishnah is me’abberin, with the letter alef.

מאן דתני ״מאברין״⁠ — אבר אבר, ומאן דתני ״מעברין״⁠ — כאשה עוברה.

The Talmud explains: The one who taught me’abberin with an alef explained the term in the sense of limb [ever] by limb. Determination of the city’s borders involves the addition of limbs to the core section of the city. And the one who taught me’abberin with an ayin explained the term in the sense of a pregnant woman [ubbera] whose belly protrudes. In similar fashion, all the city’s protrusions are incorporated in its Shabbat limit.

מערת המכפלה, רב ושמואל, חד אמר: שני בתים זה לפנים מזה, וחד אמר: בית ועלייה על גביו.

Apropos this dispute, the Talmud cites similar disputes between Rav and Shmuel. With regard to the Machpelah Cave, in which the Patriarchs and Matriarchs are buried, Rav and Shmuel disagreed. One said: The cave consists of two rooms, one farther in than the other. And one said: It consists of a room and a second story above it.

בשלמא למאן דאמר זה על גב זה ⁠— היינו ״מכפלה״. אלא למאן דאמר שני בתים זה לפנים מזה, מאי ״מכפלה״?

The Talmud asks: Granted, this is understandable according to the one who said the cave consists of one room above the other, as that is the meaning of Machpelah, double. However, according to the one who said it consists of two rooms, one farther in than the other, in what sense is it Machpelah? Even ordinary houses contain two rooms.