Eruvin 20a

עירובין כ׳ ע״א

Learn Eruvin 20a step by step: Aramaic beside English, every question, answer and proof colour-coded.

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Topic

The laws of פסין around a well: courtyards that open into them, water that dries up or returns on שבת, and the strength of partitions even when crowds pass through.

Overview

This amud opens by finishing a rejection of a proof from a ברייתא: a fence listed twice means two types of fence, just as a tree listed twice means two types of tree. אביי then asks רבה about a חצר that opens into the area between the פסין around a well. רבה rules that one חצר may carry there but two courtyards may not. רב הונא forbids two courtyards even with an עירוב, as a גזירה, while רבא permits them with an עירוב. A ברייתא supports רבא, and the גמרא defends רב הונא by saying the ברייתא is about courtyards that physically became one. Next, רבה rules that if the well dries up on שבת the פסין stop working. אביי adds that if the water returns on שבת, they work again, because a partition made on שבת still counts; only if someone built it on purpose is carrying inside it forbidden. רבי אלעזר rules that throwing into פסי ביראות makes one חייב, which teaches that a partition still counts even when crowds walk through it. The amud ends by starting a new section on the משנה's words 'מותר להקריב לבאר', comparing the rule that a person drinking across רשויות must bring his head and most of his body inside.

Opening lines

The steps (28)

1. RejectionThe proof is rejected: two types of fence
2. Questionאביי asks about a courtyard opening into the area of the boards
3. Responseרבה: one courtyard is permitted
4. Questionאביי asks about two courtyards
5. Responseרבה: two courtyards are forbidden
6. Statementרב הונא: forbidden even with an עירוב
7. Statementרבא: with an עירוב it is permitted
8. Proofאביי brings a ברייתא that supports רבא
9. ChallengeDoes this ברייתא refute רב הונא?
10. Resolutionרב הונא explains the ברייתא as a case of joined courtyards
11. QuestionWhat if the well's water dries up on שבת?
12. ResponseNo water means no partition
13. QuestionWhat if the water dries up and then returns on שבת?
14. Responseאביי says the drying-up part is already settled
15. ResponseWater that comes back on שבת makes a valid partition again
16. Challengeרב נחמן limits the rule to throwing, not carrying
17. Resolutionרב נחמן spoke only about a partition made on purpose
18. StatementThrowing into the area between the well boards makes one liable
19. ChallengeWhy does רבי אלעזר need to say this?
20. ResolutionBoards like פסי ביראות set up in the public domain
21. ChallengeThis is also obvious, because carrying by a cistern depends on it
22. ResolutionIt counts even though many people walk through it
23. ChallengeBut רבי אלעזר already taught this
24. ProofThe earlier source: the power of partitions
25. ResolutionThe earlier statement alone would not show that רבי אלעזר agrees
26. ChallengeThen why not say only the throwing ruling?
27. ResolutionOnly one statement was said; the other was learned from it
28. StatementA new phrase from the משנה, paired with the rule of drinking across רשויות