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Bava Basra 17b

בבא בתרא י״ז ע״ב

Bava Batra 17b

Learn Bava Basra 17b step by step: Aramaic beside English, every question, answer and proof colour-coded.

Open Bava Basra 17b in Gemara Clarity

Topic

The 'wall' of a pit in the משנה, and the argument between אביי and רבא about digging next to the boundary (מצר)

Overview

The גמרא asks why the משנה starts by talking about a neighbor's pit but then says to keep away from his 'wall.' אביי (some say רב יהודה) explains that it means the wall of the neighbor's pit, and the word teaches that a pit's wall is three טפחים thick. This matters when someone sells 'a pit and its walls.' Next, אביי and רבא argue about digging right at the boundary when the neighbor has no pit yet. One version says they argue only about a field not meant for pits. Another version says they argue only about a field meant for pits, and it brings support from the rules about planting trees near a pit. The גמרא then tests both versions against the משנה, and each side defends itself: רבא with 'from the wall of his pit,' and אביי by saying the משנה is about two neighbors digging at the same time. A ברייתא about soft, crumbly rock is brought against אביי but is pushed off as a special case. A new proof about olive waste and manure begins, and it continues on the next עמוד.

Opening lines

גְּמָ׳

GEMARA

פָּתַח בְּבוֹר – וּמְסַיֵּים בְּכוֹתֶל;

He opens with a pit, and ends with a wall;

לִיתְנֵי: אֶלָּא אִם כֵּן הִרְחִיק

let it teach: unless he distanced it

מִבּוֹרוֹ שֶׁל חֲבֵירוֹ שְׁלֹשָׁה טְפָחִים!

from the pit of his fellow three handbreadths!

The steps (25)

  1. ChallengeWhy does the משנה switch from 'pit' to 'wall'?
  2. ResolutionThe משנה means the wall of the neighbor's pit
  3. ChallengeThen why not just say 'pit'?
  4. ResolutionThe wording teaches that a pit's wall is three טפחים
  5. ProofWhere this matters: selling a pit and its walls
  6. Statementאביי and רבא argue about digging next to the boundary
  7. StatementWhere אביי and רבא actually disagree
  8. Statementאביי's reason: the neighbor's field is not meant for pits
  9. Statementרבא's reason: the neighbor may also change his mind
  10. StatementA second version of where the argument is
  11. Statementאביי: allowed even according to the Rabbis about trees
  12. Statementרבא: forbidden even according to רבי יוסי
  13. ProofAn inference from the משנה: with no pit, one may dig close
  14. ChallengeThe משנה fits the second version
  15. ChallengeIn the first version, the משנה is a problem for רבא
  16. Resolutionרבא answers: the משנה means measuring from the pit's wall
  17. StatementAnother telling: the same 'wall of his pit' statement
  18. ChallengeThe first version fits this reading of the משנה
  19. ChallengeIn the second version, the משנה is a problem for אביי
  20. Resolutionאביי explains the משנה as both neighbors digging at once
  21. ChallengeA teaching about soft rock seems to go against אביי
  22. RejectionSoft rock is a special case
  23. QuestionWhy did anyone bring this proof at all?
  24. ResponseThe questioner thought soft rock was mentioned to limit the distance
  25. ChallengeA new source begins: keeping olive waste and manure away