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Eruvin 83a

עירובין פ״ג ע״א

Learn Eruvin 83a step by step: Aramaic beside English, every question, answer and proof colour-coded.

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Topic

Loaf fractions and the size of a חצי פרס, and how the different סאה measures compare in eggs.

Overview

The משנה (82b) listed fractions of a loaf. Half the loaf is for entering a בית המנוגע, and a quarter, the חצי פרס, makes the body פסול for תרומה. A ברייתא adds an eighth of the loaf for טומאת אוכלין. The גמרא explains that our משנה left this out because the sizes do not match exactly: a חצי פרס is about two eggs, but never exactly two, while a כביצה is an egg with or without its shell. רב חסדא then says that two-egg view follows רבי יהודה and רבי יוסי, while רבי יוחנן בן ברוקה holds a חצי פרס is one and a half large eggs. Next רב דימי reports that רבי measured an old סאה at 217 eggs. The גמרא shows this fits no known סאה, then explains it as a ציפורי סאה of 207 eggs plus רבי's small extra twentieths. A ברייתא then says the ציפורי סאה is one-third larger than the desert סאה. When the math does not fit, רבי ירמיה reads it as approximate, and רבינא reads it as exact once רבי's extras are included. The amud ends by opening a new ברייתא on the verse 'the first of your dough', which continues on the next amud.

Opening lines

תָּנָא:

A Sage taught:

וַחֲצִי חֲצִי חֶצְיָהּ

and half of half of its half (one eighth of the loaf)

לְטַמֵּא טוּמְאַת אוֹכָלִין.

is the size to become impure with the impurity of foods.

וְתַנָּא דִּידַן מַאי טַעְמָא

And our Tanna, what is the reason

The steps (24)

  1. StatementA ברייתא adds an eighth of the loaf for food impurity
  2. QuestionWhy did our משנה leave out food impurity?
  3. ResponseThe sizes do not match exactly
  4. ProofHow big is a חצי פרס? About two eggs
  5. ProofHow big is a כביצה for food impurity?
  6. Statementרב חסדא: whose view is the two-egg חצי פרס?
  7. ChallengeIsn't this obvious?
  8. ResolutionThe new point is that the eggs are large
  9. Statementרבי measured an old סאה and found 217 eggs
  10. Challenge217 eggs fits no known סאה
  11. ChallengeEven the Tzippori measure does not match
  12. ResolutionIt is the Tzippori measure, with the חלה added
  13. ChallengeThe חלה amount is too small to close the gap
  14. ResolutionAdd the small extras in רבי's own measuring
  15. ChallengeIf so, the total comes out slightly above 217
  16. ResolutionLess than a full egg is not counted
  17. StatementA ברייתא on how the three סאה sizes compare
  18. ChallengeOne-third of the desert סאה does not fit
  19. ChallengeOne-third of the Jerusalem סאה does not fit either
  20. ChallengeOne-third of the ציפורי סאה does not fit either
  21. ResolutionThe numbers in the ברייתא are only approximate
  22. ChallengeThe ברייתא never says 'close to'
  23. ResolutionWith רבי's additions, the comparison is exact
  24. StatementNew ברייתא: 'the first of your dough'