Shabbos 149a

שבת קמ״ט ע״א

Shabbat 149a

Learn Shabbos 149a step by step: Aramaic beside English, every question, answer and proof colour-coded.

Open Shabbos 149a in Gemara Clarity

Topic

Reading lists on שבת (רב ביבי vs. אביי and the high-wall case), mirrors, captions under images, and drawing lots for portions

Overview

The משנה forbids reading a written list of guests and dishes on שבת. רב ביבי says this is a גזירה in case the host erases something, and אביי says it is a גזירה in case he comes to read שטרי הדיוטות (business documents). The גמרא searches for a case where the two reasons give different rulings. It tries writing high on a wall, then writing low on a wall, then writing engraved on a tablet, and each attempt is challenged. In the end it returns to the high-wall case. It answers the challenge from רבה, who forbids reading by a lamp at any height, by showing that רבה's strict view is one side of a dispute between תנאים: the first תנא forbids even high writing, while רבי אחא permits it. A parallel dispute about mirrors follows, where רבי מאיר permits a mirror fixed to the wall because a metal mirror itself could be used to cut hairs. A ברייתא then forbids reading captions under pictures on שבת, and forbids looking at idolatrous images even on weekdays, because that pushes God out of one's mind (רבי חנין). Finally, the גמרא explains that drawing lots for portions is allowed only with family, based on שמואל's rule about diners who are strict with each other, and that statement continues on the next amud.

Opening lines

The steps (29)

1. QuestionWhat is the reason for the prohibition?
2. Responseרב ביבי: in case he erases
3. Responseאביי: in case he reads business documents
4. QuestionWhat is the practical difference between them?
5. ResponseFirst suggestion: writing high on a wall
6. Challengeרב ביבי should also worry about reading
7. ChallengeEven high up, we still worry: the lamp case
8. ResolutionSecond suggestion: writing low on a wall
9. ChallengeChallenge to the low-wall answer: the reading view should also worry about erasing
10. ResolutionNew answer: engraved writing on a tablet or board
11. ChallengeChallenge: the erasing view should also worry about reading
12. ChallengeBlocking the escape: a ברייתא treats tablets differently from walls
13. QuestionWhat case is the ברייתא talking about? Ink writing does not fit
14. ProofThe ברייתא must mean engraved writing, so the tablet is forbidden because of reading
15. ResolutionBack to the first answer: high writing on a wall, and רבה's view is a dispute among תנאים
16. ProofSource for the dispute: the first תנא and רבי אחא
17. QuestionWhat case does רבי אחא permit?
18. Conclusionרבה's view is a dispute between תנאים
19. StatementA parallel dispute about mirrors on שבת
20. ChallengeWhy should a fixed mirror be different?
21. ResolutionThe case is a metal mirror
22. ProofWhy a metal mirror is forbidden
23. StatementWriting under a picture may not be read on שבת
24. StatementLooking at an idolatrous image is forbidden even on weekdays
25. QuestionHow does the verse teach this?
26. ResponseDo not push God out of your mind
27. StatementDrawing lots allowed with family, not with others
28. QuestionWhy not with outsiders?
29. ResponseGroup members who are strict with each other violate measuring rules