Eruvin 8a

עירובין ח׳ ע״א

Learn Eruvin 8a step by step: Aramaic beside English, every question, answer and proof colour-coded.

Open Eruvin 8a in Gemara Clarity

Topic

A מבוי ending into a רחבה or courtyard, and partitions that might change or fail

Overview

The גמרא explains what רב and שמואל argue about regarding a מבוי that opens into a רחבה. Without a shared עירוב, they argue about an opening that looks closed from outside but open from inside (נראה מבחוץ ושוה מבפנים). With an עירוב, they argue about רב יוסף's rule that only a מבוי ending in the middle of the רחבה is permitted. רבה adds that the openings must not line up, and רב משרשיא adds that the רחבה must belong to many people, since a single owner may build on it. The source for this is a case brought before רבי: a מבוי closed by the sea and an אשפה, where he gave no ruling because those barriers might change. A private heap may be cleared away while a public one stays, and the same is true of a backyard. In practice, carrying in such a מבוי is forbidden. מרימר fenced סורא's alleys with nets, and רב חסדא rejected a loose mat as a לחי unless it is fastened with a peg. Finally, the גמרא examines רב's ruling about a מבוי breached into a courtyard and shows that it teaches something beyond the משנה and the ברייתא. That discussion continues on the next amud.

Opening lines

The steps (23)

1. QuestionWhat exactly is the argument in each case?
2. ResponseWithout an עירוב: the alley that looks closed from outside but open from inside
3. ResponseWith an עירוב: they argue about רב יוסף's rule
4. Statementרבה adds a limit: the openings must not line up
5. StatementOnly a shared backyard qualifies, not a privately owned one
6. QuestionWhere do we get the private-versus-public distinction?
7. Proofרבי gave no ruling on an alleyway closed by the sea and a garbage heap
8. ResponseWhy רבי neither forbade nor permitted
9. ChallengeChallenge: elsewhere we do not worry that a garbage heap will be removed
10. ResolutionA public garbage heap differs from a private one
11. ConclusionThe same distinction applies to a backyard
12. QuestionWhat did the Sages hold in רבי's case?
13. ResponseFirst version: the חכמים forbid, and the הלכה follows them
14. ResponseSecond version: the חכמים permit, but the הלכה does not follow them
15. Statementמרימר blocks סורא's alleys with nets
16. StatementA rolled mat placed at the bend of a crooked alley
17. Rejectionרב חסדא rejects the mat under both רב and שמואל
18. ConclusionA mat fastened with a peg does count
19. Statementרב's ruling on an alley breached into a courtyard
20. ChallengeIsn't this already taught in our משנה?
21. ResolutionThe משנה might apply only where the public doesn't walk through
22. ChallengeA ברייתא already says public traffic doesn't matter for שבת
23. ResolutionThe ברייתא might apply only when the openings aren't lined up