Eruvin 55a

עירובין נ״ה ע״א

Learn Eruvin 55a step by step: Aramaic beside English, every question, answer and proof colour-coded.

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Topic

Three readings of 'לא בשמים היא' about acquiring תורה. Then a ברייתא on how a city's outline is set for the תחום שבת, and רב הונא's 4,000-אמה rule for a bow-shaped city.

Overview

This amud finishes a section of אגדה about how a person acquires תורה. אבדימי בר חמא בר דוסא reads 'לא בשמים היא' as saying that you must chase תורה even to the heavens or across the sea. רבא and רבי יוחנן read the same verse differently: תורה is not found in arrogant people, in people who think they know it all, or in merchants who are always traveling. Then the גמרא returns to the משנה's topic with a ברייתא. It explains how a city's outline is set, based on the city's shape, before the 2,000 אמה of the תחום שבת are measured from it. The גמרא then goes through the ברייתא line by line, using 'פשיטא' and 'לא צריכא' to show what each rule adds. רב הונא rules that a bow-shaped city is filled in only if its two ends are less than 4,000 אמות apart. The גמרא points out that this seems to contradict his 141⅓ rule for a breached wall, and רבה בר עולא resolves it: one case has a gap on one side, the other is split on two sides. Finally, the גמרא asks why רב הונא needed the breached-wall rule at all, and begins quoting a משנה that continues on the next amud.

Opening lines

The steps (18)

1. Statementתורה must be pursued even to the heavens
2. Statementתורה is not found in those who think they are above it
3. Statementתורה is not found in the arrogant or in traveling merchants
4. QuestionBack to the משנה: how are city boundaries extended?
5. ResponseCity shapes: long, round, square, and uneven
6. ResponseHouses that stick out from the city
7. ResponseA city shaped like a bow or the letter gamma
8. ChallengeIsn't the rule for a long city obvious?
9. ResolutionThe case is a long, narrow city
10. ChallengeIsn't the rule for a square city obvious?
11. ResolutionThe case is a square that is turned at an angle
12. ChallengeWhy mention two protruding houses?
13. ResolutionTwo houses sticking out on two different sides
14. StatementA city shaped like a bow or a gamma
15. Statementרב הונא limits the bow rule to 4,000 cubits
16. Challengeרב הונא elsewhere says 141⅓ cubits is enough to split a city
17. ResolutionOne side versus two sides
18. ChallengeWhy would רב הונא repeat a rule he already taught?