Bava Batra

If [the owner of the vineyard] neglects the matter and does not restore it, he causes his neighbour's produce to become forfeit  and is responsible for his loss. [This being so,] the reason [why either can be compelled to join in putting up the wall] is because they both agreed;  but if either did not agree. he cannot be compelled. From this we infer that 'overlooking' is not regarded as a substantial damage. But may I not say that MEHIZAH means 'division', as in the verse, And the congregation's half  [mehezath. lit., 'division']. That being so, since they agreed to make a division, either can compel the other to build a wall,  from which we infer that overlooking is recognised as a substantial damage! — If that is the case,  why does the Mishnah say. WHO AGREED TO MAKE A DIVISION [MEHIZAH]? It should say, 'who agreed lahazoth [to divide]'? — You  say then that MEHIZAH means a wall. Why then does the Mishnah say. THEY MUST BUILD THE WALL? It should say simply. 'They must build it'? — If the Mishnah had said 'it', I should have understood that a mere fence of sticks is sufficient. It tells us [therefore that the partition must be a wall]. THEY MUST BUILD THE WALL IN THE MIDDLE. Surely this is self-evident? — It had to be stated in view of the case where one of the partners had to persuade the other to agree. You might think that in that case the second can say to the first: When I consented to your request. I was willing to lose part of my air space.  but not part of my ground space.  Now we know [that he cannot say so]. But is then overlooking no substantial damage? Come and hear: SIMILARLY WITH AN ORCHARD?  — There is a special reason in the case of an orchard, as we find in a saying of R. Abba; for R. Abba said in the name of R. Huna, who said it in the name of Rab: It is forbidden to a man to stand about in his neighbour's field when the corn In It is In the ear.  But the Mishnah says AND SIMILARLY?  — This refers to the gebil and the gazith. Come and hear:  'If the wall of a courtyard falls in, he [the joint owner] can be compelled to help in rebuilding to a height of four cubits'?  — If it falls, the case is different.  But what then was the point of the objection?  — Because it could be said that this statement was required only as an introduction to the next, which runs, 'Above four cubits he is not compelled to help in rebuilding.'  Come and hear: [Every resident in a courtyard] can be compelled to assist in building a gateway and a door to the courtyard.  This shows, does it not, that overlooking is a substantial damage? Injury inflicted by the public is in a different category. Is then overlooking by a private individual not an injury? Come and hear [this]: 'A courtyard need not be divided [on the demand of one party] unless it is large enough to allow four cubits to each',  which shows that if enough space will be left to each, a division can be demanded. Must not that division be made by a wall? — No; a mere fence of sticks is sufficient. Come and hear: '[A wall built facing] windows, whether above, below, or opposite. [must be kept] four cubits away';  and in explanation of this it was taught that [if higher] it must be four cubits higher so that one should not be able to peep over and look in, and [if lower] four cubits lower so that one should not be able to stand on it and look in,  and four cubits away so as not to darken the windows? — Damage [caused by looking into] a house is different. Come and hear: 'R. Nahman said in the name of Samuel: If a man's roof adjoins his neighbour's courtyard, he must make a parapet four cubits high'?  — There is a special reason there, because the owner of the courtyard can say to the owner of the roof, I have fixed times for using my courtyard, but you have no fixed times for using your roof, and I do not know when you may be going up there