Eruvin 14b

עירובין י״ד ע״ב

Learn Eruvin 14b step by step: Aramaic beside English, every question, answer and proof colour-coded.

Open Eruvin 14b in Gemara Clarity

Topic

The size of a מקוה and the ים של שלמה; the size and placement of a לחי, and the הלכה about רבי יוסי

Overview

The amud opens by finishing a ברייתא that learns the minimum size of a מקוה from the פסוק: one אמה by one אמה, three אמות high, which the חכמים measured as ארבעים סאה. The גמרא uses this measure to check the claim that the ים של שלמה held 150 מקוואות. After working through square and round shapes, it concludes, following רמי בר יחזקאל, that the bottom three אמות were square and the top two were round. A פסוק saying the sea held 2,000 בת confirms this, and the 3,000 בת in another פסוק is explained as a heaped measure of dry goods. From this, אביי learns that a heap is one-third of the total, and a משנה in כלים supports him. A new משנה then sets the size of a לחי: ten טפחים tall and any width, while רבי יוסי requires three טפחים. The גמרא explains the plural לחיין, and adds rules about a לחי placed halfway into a מבוי and a לחי raised off the ground or set away from the wall. Finally, the הלכה about רבי יוסי is debated through conflicting reports and a retraction, and אביי answers: פוק חזי מאי עמא דבר.

Opening lines

The steps (42)

1. StatementThe verse teaches immersion in a body of water big enough for the whole body
2. StatementThe minimum size of a מקוה: 1 by 1 by 3 אמות, or ארבעים סאה
3. ChallengeThe math does not work: the ים של שלמה is too big for 150 מקוואות
4. ResolutionAnswer: the sea was round, not square
5. ChallengeNew problem: a round sea is now too small, only 125 מקוואות
6. ResolutionThe sea was square on the bottom and round on top
7. ChallengeWhy not say only the top one cubit was round?
8. ResolutionThe verse says 2,000 בת, which is exactly 150 מקוואות
9. ChallengeAnother verse says 3,000 בת
10. ResolutionThe 3,000 counts dry goods heaped above the rim
11. Statementאביי learns that a heaped load adds one-third
12. ProofA משנה in כלים supports the one-third rule
13. StatementNew משנה: the size of side posts
14. QuestionDoes the plural mean the משנה follows רבי אליעזר?
15. ResponseThe plural means side posts in general
16. ChallengeThen the cross beam משנה should also use the plural
17. ResolutionThe plural means 'those side posts they argued about'
18. QuestionHow small is 'any amount'?
19. ResponseEven as thin as a coat string
20. StatementA side post placed halfway into the alley
21. ChallengeIsn't that obvious?
22. ResolutionRead it as: he does get the inner half
23. ChallengeThat is also obvious
24. ResolutionNo worry that he will use the whole alley
25. StatementA side post raised off the ground or set away from the wall is worthless
26. ResolutionEven רבן שמעון בן גמליאל agrees, because goats can pass below
27. StatementQuoting רבי יוסי's view in the משנה
28. StatementThe הלכה does not follow רבי יוסי
29. QuestionYou only told us about brine, not about side posts
30. ChallengeWhy should brine and side posts be different?
31. ResolutionSide posts are different because רבי agrees with רבי יוסי
32. Statementרב רחומי's version: not like רבי יוסי in either case
33. QuestionDid you really say that?
34. ResponseHe answers: No
35. Rejectionרבא swears that he did say it
36. QuestionWhy did he retract?
37. ResponseBecause רבי יוסי's reasoning is with him
38. QuestionSo what is the practical הלכה?
39. ResponseGo out and see what the people do
40. StatementAnother version: the question was about the ברכה on water
41. QuestionWhat is the הלכה for the water ברכה?
42. ResponseGo see what the people do (people say שהכל)