Niddah 51a

נדה נ״א ע״א

Learn Niddah 51a step by step: Aramaic beside English, every question, answer and proof colour-coded.

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Topic

The חכמים's reply to רבי יוחנן בן נורי about נבלת עוף טהור, and רבא on plans made while produce is attached and 'type' rules for מעשר

Overview

The amud opens by explaining how the חכמים answered רבי יוחנן בן נורי. He used a קל וחומר to argue that the food-impurity of נבלת עוף טהור should not need מחשבה. The first explanation is that food-impurity spreads to similar items, but אביי shows this only makes the קל וחומר stronger. רב ששת then says the difference is הכשר. A משנה seems to say this carcass needs no הכשר, and the teaching of the school of רבי ישמעאל backs that up. Finally רבא, or some say רב פפא, explains that the חכמים compared whole categories of impurity. Next רבא says that for מעשר, even רבי יוחנן agrees that a plan made while produce is still attached counts. רב אשי rejects his proof from herbs in a courtyard and challenges him with the rule that whatever owes מעשר becomes impure as food. רבא answers that such rules speak about types (מין). A proof from a טרפה is pushed away by רבינא, but a ברייתא about an ownerless vineyard proves רבא right. The amud ends by quoting a משנה about פאה for dill or mustard sown in several spots, and the discussion continues on the next amud.

Opening lines

The steps (20)

1. StatementFirst explanation of the חכמים's reply: one impurity spreads, the other does not
2. Challengeאביי: that difference makes the argument stronger, not weaker
3. Resolutionרב ששת: the real difference is the need for הכשר
4. ChallengeChallenge: a משנה says this carcass needs no הכשר
5. ResolutionIt needs water-preparation, just not creeping-animal preparation
6. ChallengeWhy free it from one kind of preparation but not the other?
7. ProofThe school of רבי ישמעאל: only things that never carry severe impurity need preparation
8. ResolutionThe חכמים look at whole categories of impurity
9. Statementרבי יוחנן agrees that a plan made while attached counts for מעשר
10. Proofרבא brings a משנה about herbs in a courtyard
11. ProofThe משנה must mean herbs first planted for animals
12. Rejectionרב אשי: the herbs grew by themselves
13. ChallengeA משנה seems to contradict רבא's distinction
14. ResolutionThe משנה is talking about types of food
15. ProofSupport from the next part of the משנה
16. ProofThe טרפה shows the rule is about types
17. Rejectionרבינא: The משנה Follows רבי שמעון
18. ProofThe Ownerless Vineyard Owes פאה but Not מעשר
19. ConclusionSo the משנה Speaks About Types
20. StatementDill or Mustard Sown in Several Spots Needs פאה From Each