Eruvin 57b

עירובין נ״ז ע״ב

Learn Eruvin 57b step by step: Aramaic beside English, every question, answer and proof colour-coded.

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Topic

How settlements join into one city for measuring the תחום שבת: the קרפף, the three villages, and the rules for measuring the תחום.

Overview

Background: the תחום שבת is the 2,000-אמה walking limit around a city. רבי מאיר holds that a small extra zone called a קרפף (about 70⅔ אמות) is added to each city before measuring. The גמרא first shows that the משנה's two-city clause also follows רבי מאיר. It explains through a two-way צריכותא why both clauses are needed. Next it tries to refute רב הונא from the משנה about three villages, where a middle village joins the outer two. רב הונא answers with רבי חנינא's reading: the middle village may sit off to the side and is only imagined as filling the gap. רבא and אביי then work out the limits of this rule, comparing it to a bow-shaped city (עיר העשויה כקשת). רב ספרא asks how אקיסטפון and ארדשיר can join across the Tigris, and רבא shows him submerged wall foundations that close the gap. Finally a new משנה begins, teaching that the תחום is measured with a 50-אמה rope at heart level, spanning across canyons, fences and hills.

Opening lines

The steps (21)

1. QuestionWhose opinion is this teaching?
2. ResponseIt is רבי מאיר
3. ChallengeWhy repeat רבי מאיר's rule?
4. ResolutionThe first clause alone would not teach two קרפפות for two cities
5. ResolutionThe second clause alone would not teach a קרפף for one city
6. StatementQuoting the משנה about three villages
7. ChallengeInference from the משנה refutes רב הונא
8. Resolutionרב הונא reads the משנה through רבי חנינא
9. Questionרבא asks how far the middle village may be
10. Responseאביי answers: two thousand cubits
11. Challengeרבא challenges אביי from his own earlier ruling
12. Resolutionאביי rejects the comparison to the bow-shaped city
13. Questionרבא asks the distance between the two outer villages
14. Responseאביי says the outer distance does not matter
15. QuestionEven 4,000 אמות apart? Yes
16. ChallengeChallenge from רב הונא's bow-shaped city rule
17. Resolutionאביי: here the middle village fills the gap
18. ChallengeThe Tigris seems too wide to join two towns
19. ResolutionSubmerged wall foundations close the gap
20. StatementMeasure only with a fifty-אמה rope at heart level
21. StatementSpan across canyons, fences and hills