Niddah 20b

נדה כ׳ ע״ב

Learn Niddah 20b step by step: Aramaic beside English, every question, answer and proof colour-coded.

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Topic

Examining blood: which sages ruled on it and why, the limits on overturning another חכם's ruling, trusting a woman's report, and judging color by what is seen in proper light

Overview

This amud is about the skill and caution needed to examine blood (ראיית דמים). It opens by saying only the wise רבי חנינא could examine blood his special way. Then several sages explain why they did or did not examine blood: רבי יוחנן, רבי זירא, עולא and רב יהודה each held back for their own reasons, while רבי אלעזר took it on, learning from רבי חנינא's humility. Stories about רבי אלעזר and רבא, who recognized דם חימוד by smell and passed a test of sixty kinds of blood, show how great real expertise was. The story of ילתא, whose blood one sage ruled impure and another pure, raises the rule that one חכם may not overturn another's strict ruling. It also raises the question of whether a woman is believed about blood and about a חכם's ruling. Both proofs for that last question are pushed away, and it stays unresolved on this amud. The גמרא then explains רבי's three changing rulings on one stain: a judge goes only by what his eyes see. It ends with the right lighting for checking blood and returns to the משנה's color of diluted wine, with a ברייתא that continues on the next amud.

Opening lines

The steps (30)

1. StatementOnly רבי חנינא was wise enough to examine this way
2. Statementרבי יוחנן stopped examining blood because of רבי חנינא's wisdom
3. Statementרבי אלעזר began examining blood because of רבי חנינא's humility
4. Statementרבי זירא refrained because he did not understand the nature of בבל
5. ChallengeDoes blood depend on understanding nature? רבה knew one but not the other
6. Resolutionרבי זירא meant an all-the-more-so argument based on רבה
7. Statementעולא refuses to examine blood in פומבדיתא
8. QuestionWhy was רבי אלעזר called master of the land of Israel
9. Responseרבי אלעזר identifies blood of desire
10. Statementרבא identifies the queen mother's blood, and her son doubts him
11. Proofרבא passes the test of sixty kinds of blood
12. StatementWhy רב יהודה stopped examining blood
13. StatementThe one kind of case רב יהודה still examines
14. Statementילתא takes her blood to two different sages
15. ChallengeHow could the second sage rule pure after the first ruled impure?
16. ResolutionWhy רב יצחק was allowed to rule her pure
17. QuestionIs ילתא believed about this?
18. ResponseYes — a woman is believed about her blood
19. QuestionIs she believed that a חכם ruled this color pure?
20. ProofTrying to prove she is believed from the same ברייתא
21. RejectionNo proof — there the blood is gone
22. ProofA proof from the story of יַלְתָּא
23. RejectionHe relied on his own learning
24. Statementרבי rules on the same blood three times
25. ChallengeDid רבי really make a mistake?
26. ResolutionA judge rules only by what he sees
27. StatementHow different חכמים checked blood
28. StatementCheck blood between sun and shade
29. StatementIn the sun, under the shade of one's hand
30. StatementBack to the משנה: the color of diluted wine