salt, and lime, and rocks three handbreadths from the wall of another, or he can plaster the wall with lime. The Gemara analyzes this statement: The reason for this ruling is that there is a wall there belonging to his neighbor, from which it may be inferred that if there is no wall there, one may place these substances close to the boundary of his neighbor’s courtyard. This presents a difficulty for the opinion of Rava according to the first version of the dispute, which states that one may not place these substances close to a boundary even in the case of a field that is not designated for pits.

The Gemara rejects this proof: No, even if there is no wall one may also not place these substances close to the boundary. The Gemara asks: Rather, what does mentioning a wall here teach us? The Gemara answers: This teaches us that all these substances are damaging to a wall.

The Gemara suggests: Come and hear another proof from the mishna: One must distance seeds, and the plow, and urine three handbreadths from the wall of another. The Gemara analyzes this ruling: The reason for this ruling is that there is a wall, from which it may be inferred that if there is no wall, one may place these substances close to the boundary of the field. The Gemara rejects this proof as well: No, even if there is no wall, one may also not place these substances close by the boundary. The Gemara asks: But rather, what does this teach us? The Gemara answers: This teaches us that dampness [dimtunta] is damaging to a wall.

The Gemara suggests: Come and hear another proof from the mishna: And one must distance a mill from a wall by three handbreadths from the lower stone of the mill, which is four handbreadths from the upper stone. The Gemara analyzes this statement: The reason for this ruling is that there is a wall, from which it may be inferred that if there is no wall, one may place a mill close by the boundary. The Gemara rejects this proof: No, even if there is no wall, one may also not place his mill close by the boundary. The Gemara asks: But rather, what does this teach us? The Gemara answers: This teaches us that vibrations are damaging to a wall.

The Gemara suggests: Come and hear another proof from the mishna: And the oven must be distanced three handbreadths from the base, which is four handbreadths from the upper rim of the oven. The Gemara analyzes this statement: The reason for this ruling is that there is a wall, from which it may be inferred that if there is no wall, one may place an oven close by the boundary. The Gemara rejects this proof as well: No, even if there is no wall, one may also not place his oven close by the boundary. The Gemara asks: Rather, what does this teach us? The Gemara answers: This teaches us that heat is damaging to a wall.

The Gemara suggests: Come and hear a proof from the mishna (20b): A person may not open a bakery or a dye shop beneath the wine storeroom of another, nor may one open a cattle barn there. The Gemara analyzes this mishna: The reason for this ruling is that there is a storeroom already in place, from which it may be inferred that if there is no storeroom one may do so. If this is the case, then with regard to a pit as well, one may dig next to a boundary if there is as yet no pit.

The Gemara answers: The case of a residence is different, as in general one can use his domicile in any manner of his choosing unless he directly causes damage to another or his property. The Gemara adds: The language of the mishna is also precise, as an explicit baraita is taught with regard to that mishna: If the construction of the cattle barn preceded the storeroom, it is permitted. Nothing can be inferred from the case of the baraita with regard to the halakha of the mishna, which does not concern living quarters.

The Gemara suggests: Come and hear a proof from a mishna (26a): A person may not plant a tree close to another’s field unless he distances it four cubits from his neighbor. And it is taught with regard to this mishna: The four cubits of which the Sages spoke are to enable the work of the vineyard, i.e., a small space next to the trees is necessary to enable animals to plow between them.

The Gemara analyzes this ruling: The reason this distance is required is due to the work of the vineyard, from which it may be inferred that if not for the problem due to the work of the vineyard, it would be permitted for one to plant his tree close to the boundary, and apparently, this is the halakha even though there are roots of the tree that damage his neighbor’s field. The Gemara answers: With what are we dealing here? We are dealing with a case where a hard rock [tzunema] interrupts between the two fields, preventing the roots from passing through to the other field.

The Gemara continues: The language of the mishna is also precise with regard to this point, as it teaches further on: If there was a fence between them, this one places, i.e., plants a tree, close to the fence from here, and that one places, i.e., plants a tree, close to the fence from here. If the baraita were referring to a case where the roots could travel across, how could it be permitted for both neighbors to plant their trees alongside each other? Consequently, it must be referring to a situation where a rock separates between the two fields below, and therefore the neighbors may plant their trees near the fence.

The Gemara responds: If so, say the last clause of that mishna: If the roots of the tree extended into the field of another, the neighbor may cut them off to a depth of three handbreadths, so that they do not impede the plow. The Gemara asks: But if a rock interrupts between the two fields and forms a barrier, what are these roots doing there, i.e., how did they get there? The Gemara answers: This is what the tanna of the mishna is saying: And if there is no rock, and the roots of the tree extended into the field of another, the neighbor may cut them off to a depth of three handbreadths so that they do not impede the plow.

The Gemara suggests: Come and hear a proof from a mishna (25b): One must distance a tree twenty-five cubits from a cistern. The Gemara analyzes this halakha: The reason for this ruling is that there is a cistern, from which it may be inferred that if there is no cistern, one may place, i.e., plant, his tree close to the neighbor’s field. The Gemara answers: No, even when there is no cistern one may also not place it close to the neighbor’s field. And by mentioning a cistern, the tanna of the mishna teaches us this: That the roots of a tree extend and damage the cistern up to a distance of twenty-five cubits away.

The Gemara asks: If so, say the last clause of that mishna: And if the tree preceded the cistern, one is not required to cut down the tree. But if one may not place the tree close to the boundary even if there is no cistern, how can you find a case where the tree preceded the cistern? Why would its owner not be required to cut it down? The Gemara answers: This is as Rav Pappa says with regard to a similar matter, that it is referring to a buyer who purchases part of a field. So too here, it is referring to a buyer. In other words, a field contained a cistern and tree alongside each other, and the owner sold the part of the field containing the cistern.

The Gemara cites yet another source: Come and hear a proof from a mishna (25a): One must distance the water in which flax is steeped from vegetables growing in a neighbor’s field, and one must distance leeks from onions growing in a neighbor’s field, and one must likewise distance mustard from bees that are in a neighbor’s field. The Gemara analyzes this statement: The reason is that there are vegetables present, from which it may be inferred that if there are no vegetables, one may place the water close to the neighbor’s field. The Gemara rejects this opinion: No, even if there are no vegetables one may also not place the water close to the neighbor’s field. And the tanna teaches us that these items mentioned in that mishna are harmful to each other.

The Gemara responds: If so, say the last clause of that mishna: Rabbi Yosei renders it permitted to plant near the neighbor’s bees in the case of mustard. As explained in a baraita, this is because he can say to the owner of the bees: Just as you say to me: Keep your mustard away from my bees, I can say to you: Keep your bees away from my mustard, as they come and eat my mustard plants. In other words, you are damaging my property as well.