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Bava Basra 18a

בבא בתרא י״ח ע״א

Bava Batra 18a

Learn Bava Basra 18a step by step: Aramaic beside English, every question, answer and proof colour-coded.

Open Bava Basra 18a in Gemara Clarity

Topic

Does a משנה that names a neighbor's wall, storeroom, pit or plants prove that, where these are absent, one may place damaging things right at the boundary? The amud tests רבא's view against אביי.

Overview

Before this amud, אביי and רבא argued about a field that is not set aside for pits. In the first version, רבא says one must still keep damaging things away from the boundary. The גמרא now brings one source after another that seems to say the distance is needed only when the neighbor already has something there. First come four cases that say to keep away 'from the wall': salt, lime and rocks; seeds, plowing and urine; a mill; and an oven. Each time the גמרא answers that the distance is needed even with no wall. The wall is mentioned only to teach what harms walls: these materials, dampness, shaking, and heat. The storeroom case is pushed aside because a home is different. The tree-near-a-field case is explained as fields with a rock underground between them. The tree-and-cistern case is answered by saying the cistern teaches how far roots spread, and a tree that 'came first' is explained as a case of a buyer. Last, the גמרא answers the flax-water, leeks and mustard case and then begins pressing on it using רבי יוסי's ruling about mustard and bees, which continues on the next amud.

Opening lines

הַמֶּלַח, וְאֶת הַסִּיד, וְאֶת הַסְּלָעִים

the salt, and the lime, and the rocks

מִכּוֹתְלוֹ שֶׁל חֲבֵירוֹ שְׁלֹשָׁה טְפָחִים,

three handbreadths from the wall of his fellow,

אוֹ סָד בְּסִיד.

or he plasters [the wall] with lime.

טַעְמָא דְּאִיכָּא כּוֹתֶל,

The reason is that there is a wall,

The steps (28)

  1. ChallengeThe משנה says 'from his neighbor's wall', so maybe no wall means no distance
  2. RejectionNo, even without a wall you must keep away
  3. ResponseWhy mention the wall? These materials harm walls
  4. ChallengeSecond try: seeds, plowing and urine 'from the wall'
  5. RejectionNo, even without a wall you must keep away
  6. ResponseWhy mention the wall? Dampness harms walls
  7. ChallengeThird try: the mill kept away from the wall
  8. RejectionNo, even without a wall you must keep away
  9. ResponseWhy mention the wall? A mill's shaking harms walls
  10. ChallengeThe oven case seems to allow building at the boundary when there is no wall
  11. RejectionEven with no wall, the oven may not be placed at the boundary
  12. ResponseThe wall is mentioned to teach that heat damages a wall
  13. ChallengeThe storeroom case seems to allow a shop when there is no storeroom yet
  14. ResolutionA home is a different case
  15. ProofSupport from the ברייתא: if the barn came first, it is allowed
  16. ChallengeSetting up a new proof from planting a tree near a field
  17. ChallengeThe vineyard reason suggests roots don't matter
  18. ResolutionA rock underground blocks the roots
  19. ProofThe fence clause supports the rock case
  20. ChallengeThen how do roots reach the neighbor?
  21. ResolutionThe last clause is a separate no-rock case
  22. ChallengeThe tree and the בּוֹר: no בּוֹר means plant close?
  23. ResolutionThe בּוֹר teaches how far roots spread
  24. ChallengeIf a tree may never be planted close, how can it come first?
  25. ResolutionThe tree came first in a case of a buyer
  26. ChallengeA new משנה seems to allow placing close when nothing is there
  27. ResolutionThe משנה only teaches that these things harm each other
  28. ChallengeQuoting רבי יוסי on mustard to challenge the answer