Siman - Eruvin Daf 55

  • לא בשמים היא

The Gemara presents three different interpretations of the passuk, לא בשמים הוא...ולא מעבר הים הוא – The [Torah] is not in the heavens nor is it across the oceans.

·Avdimi bar Chama bar Dosa said, שאם בשמים היא אתה צריך לעלות אחריה – that if it were in the heavens, you would be required to ascend there to reach it, ואם מעבר הים היא אתה צריך לעבור אחריה – and if it were across the ocean, you would have to cross it to reach it.

·Rava said, לא תמצא במי שמגביה דעתו עליה כשמים – Torah will not be found in one who believes that his mind towers over it like the heavens, ולא תמצא במי שמרחיב דעתו עליה כים – nor will it be found in one who believes his mind is as broad as the ocean . in relation to it.

·Rebbe Yochanan said, לא תמצא בגסי הרוח – Torah will not be found in those who are arrogant, ולא תמצא לא בסחרנים ולא בתגרים – and Torah will not be found amongst traveling businessmen nor with peddlers.

  • How boundaries are drawn around cities

The Mishnah on Daf 52b addressed how the boundaries of a city are determined in order to measure the techum. On this Daf, a Baraisa is brought that addresses how to measure cities with different configurations.

ארוכה כמות שהיא – A rectangular city keeps its boundaries and is not squared off.

עגולה עושין לה זוויות – A circular city is squared off.

 - מרובעת אין עושין לה זוויות A square city keeps its boundaries, even if it is not aligned with east, west, north and south.

היתה רחבה מצד אחד וקצרה מצד אחר רואין אותה כאילו היא שוה – If it is wider on one end and narrower on the other, the boundaries are drawn as parallel lines to make it a rectangle. Other configurations are discussed as well, such as when houses stick out beyond the rest of the houses, and bow shaped or L-shaped cities  .

  • Measuring the techum for hut dwellers

Rav Huna said, יושבי צריפין – For hut dwellers, אין מודדין להן אלא מפתח בתיהן – we measure their techum only from the doors of their homes, and not from the edge of their town. Rashi explains that huts do not constitute a town since they are temporary dwellings.

Rav Chisda asked that if this is so, then how could the Jewish people in the midbar travel up to three parsaos on Shabbos to relieve themselves at the back of the camp? Meaning, if the techum was measured from the doorways of their individual tents, then they should be limited to two thousand amos from their tents. Rava answered that the דגלי מדבר were different as it says, על פי ה' יחנו – By the word of Hashem they would camp, and therefore it was כמאן דקביע להו דמי – considered as if they had a permanent encampment. Rashi explains that since their encampment was determined directly by HaKadosh Boruch Hu, it was significant, and therefore it was considered enough to be a permanent dwelling.