Kereisos 21a

כריתות כ״א ע״א

Keritot 21a

Learn Kereisos 21a step by step: Aramaic beside English, every question, answer and proof colour-coded.

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Topic

The blood prohibition: which creatures are included (including the כוי), and light versus severe טומאה for people and animals

Overview

This amud finishes a ברייתא on the פסוק "כל דם לא תאכלו... לעוף ולבהמה". The ברייתא excludes the blood of שרצים, eggs, fish and grasshoppers, and it explains why the פסוק names both bird and animal. The גמרא reads the פסוקים as a כלל ופרט וכלל, which includes anything similar to bird and animal. It explains that this follows the school of רבי ישמעאל, even though the two generalizations are not alike. The extra phrase "אף כל" includes the blood of a כוי, which רב אדא בר אבין holds is a creature of its own kind. The גמרא then finds sources for the כוי's fat, נבלה, גיד הנשה, טומאה and שחיטה. Next it resolves a contradiction about whether people get light (food) טומאה: a living person's flesh can, but a dead body cannot. Finally, a משנה about which נבילות need מחשבה and הכשר leads to a debate between רב and רבי חייא about a piece of נבילה smaller than a כזית, and that discussion continues on the next amud.

Opening lines

The steps (34)

1. StatementExcluding the blood of creeping creatures
2. StatementExcluding the blood of eggs
3. StatementExcluding the blood of fish and grasshoppers
4. ChallengeWhy the verse needs the word animal
5. ResolutionThe word animal stands on its own
6. ChallengeWhy the verse needs the word bird
7. ResolutionBird and animal each stand on their own
8. ChallengeChallenge: read the verse as a general term followed by a detail
9. ResolutionA second generalization makes it a three-part pattern
10. ChallengeThe two generalizations do not match
11. ResolutionThe school of רבי ישמעאל uses the rule anyway
12. StatementQuoting the ברייתא's features of the detail
13. QuestionWhat does 'so too anything' come to include?
14. ResponseIt includes the blood of a כוי
15. ChallengeIf the כוי is only a doubt, why would we need a פסוק?
16. ResolutionThe כוי is a creature of its own kind
17. QuestionWhere do we learn that the כוי's fat is forbidden?
18. QuestionWhere do we learn that the כוי's carcass is forbidden?
19. QuestionThe כוי's גיד הנשה is forbidden because it has a כף הירך
20. QuestionSource for the כוי's impurity and slaughter: logic
21. ChallengeHuman blood excluded because people lack light impurity, contradicted by a משנה
22. ChallengeWhy the משנה needs intent at all
23. Resolutionריש לקיש: he cut it for a dog
24. ChallengeChallenge: food for a dog does count
25. ResolutionThe dog standard only works for removing impurity
26. ChallengeBack to the contradiction: intent means light impurity
27. ResolutionA living person versus a dead person
28. ChallengeA dead animal also has only severe impurity
29. ProofProof that the blood of a dead animal is impure
30. ResolutionThe ברייתא's rule is needed for a משנה about intent and הכשר
31. Challengeרב asks why a carcass needs intent at all
32. ResolutionLess than an olive-size of carcass joined with other food
33. ChallengeThen it should also need to be made wet
34. ResolutionOrdinary food needs הכשר, but a small piece of נבילה does not