Gemara Clarity

Eruvin 9b

עירובין ט׳ ע״ב

Learn Eruvin 9b step by step: Aramaic beside English, every question, answer and proof colour-coded.

Open Eruvin 9b in Gemara Clarity

Topic

When a side post that is visible only from outside counts as a לחי, and how לבוד applies to rows of posts and to a breached courtyard.

Overview

This amud explains when a side post (לחי) counts for permitting carrying in an alley. רב אשי explains the מחלוקת about לבוד as a case of posts lined up with gaps under four טפחים for four אמות. According to רבן שמעון בן גמליאל, the posts join into a wall that forms its own מבוי, so it needs another לחי. According to the רבנן, it does not. The row of posts cannot serve as its own לחי, because רבי יוחנן rules that a post 'visible from outside, flush inside' is not a לחי. The גמרא then shows that רבי חייא, who taught a ברייתא saying such a post does count, holds the opposite view. A sage who teaches a ruling is assumed to agree with it. רבה בר רב הונא rules like רבי חייא. He is challenged from the משנה of a small courtyard breached into a large one. רבי זירא, רבינא and the גמרא then debate whether לבוד can close the gaps around the opening. The amud ends with the question of whether לבוד on one side alone is enough.

Opening lines

רַב אָשֵׁי אָמַר:

Rav Ashi said:

כְּגוֹן שֶׁרְצָפוֹ בִּלְחָיַיִם

for example, where one lined it with side posts

פָּחוֹת פָּחוֹת מֵאַרְבָּעָה

each less than four (handbreadths) apart

בְּמֶשֶׁךְ אַרְבַּע אַמּוֹת.

for a length of four cubits.

The steps (15)

  1. Statementרב אשי describes a new case: an alley lined with side posts
  2. StatementHow each side rules in רב אשי's case
  3. ChallengeWhy not treat the row as a valid side post?
  4. Resolutionרבי יוחנן holds such a post does not count
  5. StatementA recorded dispute about a post that sticks out on only one side
  6. ProofProving that רבי חייא is the one who says it counts
  7. RejectionChallenge: maybe רבי חייא knew the ruling but did not follow it
  8. ResolutionAnswer: nobody teaches a ruling he rejects
  9. StatementA post visible outside but flush inside counts as a לחי
  10. ChallengeChallenge from the small courtyard breached into a large courtyard
  11. ResolutionThe small courtyard's walls stick into the large one
  12. ChallengeWhy not close the gap with לבוד?
  13. ChallengeBlocking the reply that the gaps are too wide
  14. Resolutionרבינא: the gaps are uneven, two handbreadths on one side and four on the other
  15. ChallengeLet the narrow two-handbreadth side work on its own