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Eruvin 78a

עירובין ע״ח ע״א

Learn Eruvin 78a step by step: Aramaic beside English, every question, answer and proof colour-coded.

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Topic

How ledges, ladders and stakes change the status of walls and pillars: lowering a wall between courtyards, and cancelling a pillar's status as a רשות היחיד.

Overview

A wall at least ten טפחים high fully separates two courtyards. This amud asks when a ledge (זיז) or a ladder (סולם) makes such a wall count as lower, so people can cross it. A 4-by-4 זיז with a ladder leading onto it lowers the wall, and a 20-טפח wall needs two staggered זיזים. In the middle, the גמרא turns to a pillar in רשות הרבים: does a stake driven into its top cancel its status as a רשות היחיד? רב אדא, אביי and רבא, and רב אשי each give a different answer, and רב אשי proves his view from רבי יוחנן's rule about a pit and its rim. Next, אמוראים argue about how long a ladder must be for a ten-טפח wall, from fourteen טפחים down to seven and a bit if it stands upright. שמואל explains רב's tradition that even an upright ladder counts. The amud ends with heavy Babylonian palm trunks and ladders that count as fixed in place. Last is רבה's test for combined ladders: they count only if the foot can climb in the middle.

Opening lines

זִיז הַיּוֹצֵא מִן הַכּוֹתֶל

A ledge that sticks out from the wall

אַרְבָּעָה עַל אַרְבָּעָה,

four by four handbreadths

וְהִנִּיחַ עָלָיו סוּלָּם כׇּל שֶׁהוּא

and he placed against it a ladder of any width

— מִיעֲטוֹ.

he has reduced it (the wall's height)

The steps (26)

  1. StatementA ledge with a ladder lowers the wall
  2. StatementThe ladder must lead onto the ledge, not stand beside it
  3. StatementA nineteen-handbreadth wall needs one ledge
  4. StatementA twenty-handbreadth wall needs two ledges
  5. StatementThe two ledges must not be directly one above the other
  6. StatementA stake of any size reduces a pillar's surface
  7. StatementThe stake must be three טפחים high
  8. StatementEven a stake shorter than three reduces it
  9. ResponseWhy a short stake still counts
  10. StatementEven a three-טפחים stake does not reduce it
  11. QuestionWhat if the whole pillar top is filled with stakes?
  12. Responseרב אשי points to רבי יוחנן's rule about a pit and its rim
  13. ProofJust as a board is laid over the pit, a board can be laid over the stakes
  14. StatementA ten-handbreadth wall needs a fourteen-handbreadth ladder
  15. Statementרב יוסף: thirteen handbreadths and a bit is enough
  16. Statementאביי: eleven טפחים and a bit is enough
  17. Statementרב הונא בריה דרב יהושע: seven טפחים and a bit is enough
  18. Statementרב's tradition: an upright ladder reduces the wall's height
  19. Responseשמואל explains: like one platform on top of another
  20. StatementBabylonian palm trunks do not need to be fixed in place
  21. StatementBabylonian ladders do not need to be fixed in place
  22. ConclusionHow far each of the two traditions reaches
  23. QuestionTwo narrow ladders with straw rungs between them
  24. ResponseStraw in the middle does not count because the foot cannot climb on it
  25. QuestionWhat if the straw is on the sides and the ladder is in the middle?
  26. ResponseLadder in the middle counts because the foot can climb on it