Eruvin 5a

עירובין ה׳ ע״א

Learn Eruvin 5a step by step: Aramaic beside English, every question, answer and proof colour-coded.

Open Eruvin 5a in Gemara Clarity

Topic

How long a raised or dug-out area at a מבוי's entrance must be, according to רב יוסף and אביי, and the proofs each side brings.

Overview

The amud opens by finishing an argument between רב יוסף and אביי. A מבוי whose קורה is too high can be fixed by raising the floor under it, and they argue how far that raised floor must reach: one טפח (רב יוסף) or four טפחים (אביי). The גמרא rejects the idea that they argue about using the space under the קורה. It then gives three other explanations: whether a קורה works as a היכר or as a מחיצה, whether a marker on the ground counts like a marker overhead, and whether there is a גזירה in case the raised floor wears down. Next comes a new case: a קורה lower than ten טפחים, where the ground beneath it is dug out. Here רב יוסף says the dug area must extend four טפחים and אביי says four אמות. The גמרא suggests their argument depends on רבי אמי ורבי אסי's ruling about a breached מבוי, but rejects this, because keeping an existing מבוי valid is different from creating a new one. אביי then brings two proofs that a מבוי needs four אמות, one from a ברייתא about courtyards and one from רב הונא's ruling about a protruding לחי, and רב יוסף answers both. Finally, with the word גופא, the גמרא begins to study רב הונא's ruling on its own, and that discussion continues on the next amud.

Opening lines

The steps (19)

1. StatementThe opinion requiring four טפחים forbids using the space under the beam
2. RejectionRejected: everyone permits using the space under the beam; the real question is marker versus wall
3. ResponseSecond explanation: does a marker on the ground count like a marker overhead?
4. ResponseThird explanation: a decree in case the raised floor wears down
5. QuestionDigging out the floor under a low beam: how much?
6. ChallengeThe depth question is obvious
7. ResolutionThe real question: how long must the dug area be?
8. ResponseFour handbreadths or four cubits
9. QuestionIs this argument tied to רבי אמי and רבי אסי?
10. ProofThe ruling about a breached alley wall
11. StatementMatching each view to רבי אמי
12. RejectionA damaged alley is different from a new one
13. Proofאביי brings his source: courtyards must open into the alleyway
14. ChallengeA four-handbreadth alleyway has no room for courtyards
15. RejectionOpening through the back wall does not work
16. Resolutionרב יוסף: the doorways open at the corners
17. Proofאביי brings proof from a protruding side post
18. Rejectionרב יוסף separates losing side-post status from becoming an alleyway
19. StatementStudying רמי בר חמא's statement on its own