Eruvin 79a

עירובין ע״ט ע״א

Learn Eruvin 79a step by step: Aramaic beside English, every question, answer and proof colour-coded.

Open Eruvin 79a in Gemara Clarity

Topic

Cancelling a space by filling it (house versus ditch), planks over ditches and between balconies, and a haystack as a wall between two courtyards.

Overview

The amud opens by finishing a contradiction. Our משנה says a ditch filled with dirt or pebbles is cancelled automatically, while the משנה in אהלות says a filled house is cancelled only if the owner actively cancels it. רב הונא says אהלות follows רבי יוסי, but a ברייתא shows רבי יוסי holds the opposite, so רב אסי says עירובין follows רבי יוסי instead. רב הונא בריה דרב יהושע answers that שבת and טומאה are different: for שבת, a person treats even a money-pouch as fixed for the day. רב אשי answers that a ditch is meant to be filled and a house is not. רבא then explains the משנה's lines about a plank over a ditch and a plank between balconies, using the rule of לבוד. A new משנה teaches that a haystack ten טפחים high is a wall between two courtyards. רב הונא forbids taking hay from it into a basket, and the גמרא defends him against a ברייתא about a house filled with hay. Finally, the גמרא tries to prove from that ברייתא that walls not reaching the ceiling still count. אביי rejects the proof, and רב הונא בריה דרב יהושע begins a second rejection that continues on the next amud.

Opening lines

The steps (22)

1. ChallengeFinishing the contradiction from אהלות
2. Resolutionרב הונא: אהלות follows רבי יוסי
3. ChallengeBut רבי יוסי holds the opposite
4. ProofThe ברייתא: what matters is whether he plans to remove it
5. Resolutionרב אסי: עירובין follows רבי יוסי
6. Resolutionטומאה and שבת cannot be compared
7. ResolutionA ditch is meant to be filled, but a house is not
8. StatementA plank placed along the length works even if it is narrow
9. StatementBalconies must face each other directly
10. StatementA gap under three handbreadths makes it one bent balcony
11. StatementA haystack ten handbreadths high acts as a wall between courtyards
12. Statementרב הונא limits how animals may be fed from the haystack
13. ChallengeChallenge: standing an animal next to the haystack should also be forbidden
14. ResolutionAnswer: the owner only blocks the animal, and it eats on its own
15. ChallengeChallenge from a ברייתא that openly allows taking hay into a basket
16. ChallengeThe ברייתא explains how to fix the problem once the hay drops below ten
17. ChallengeSame rule for a hay pit, and the גמרא pinpoints the contradiction
18. ResolutionA house is different because the drop in hay is noticeable
19. StatementThe גמרא quotes the ברייתא's line about hay dropping below ten
20. ProofPartitions that do not reach the ceiling still count
21. Rejectionאביי: The house was just under thirteen handbreadths, so the hay is joined to the ceiling
22. Rejectionרב הונא בריה דרב יהושע: Even in a house ten טפחים high