Bava Batra

For what purpose is the new rule laid down by Resh Lakish?  — [In order to tell us] that if the vendor desires to let out projecting spars from the roof, he is at liberty to do so.  R. Papa says: [In order to tell us] that if he desires to build an upper chamber over the apartment, he is at liberty to do so.  Accepting R. Zebid's view, we understand why Resh Lakish used the expression 'this shows'.  But on the view of R. Papa, why should he have said, 'this shows'?  — This is really a difficulty. R. Dimi of Nehardea said: If a man sells an apartment to another,  even though he inserts in the deed of sale the words, '[I sell you] the depth and the height',  he must further insert the words, 'Acquire for thyself possession from the depth of the earth to the height of heaven,' because the space below and above is not transferred automatically.  Hence the words 'depth and height' avail to transfer the space below and above, while the words 'from the depth of the earth to the height of heaven' avail to transfer a well, a cistern and cavities. Shall we say [that the following Mishnah] supports R. Dimi: The vendor does not transfer the well and the cistern even though he inserts the words 'depth and height'?  Now if you should assume that the space below and above is transferred automatically, then the insertion of the words 'depth and height' should avail to transfer well, cistern and cavities [should they not]? — [We suppose the Mishnah to refer to the case] where these words were not inserted.  But the Mishnah distinctly says, 'although he inserts the words [depth and height']? — We must explain the Mishnah thus: Even if these words are not actually inserted they are regarded as being inserted for the purpose of transferring the space below and above; and as regards a well and a cistern, if the words 'depth and height' are inserted, these are transferred, but otherwise not. Come and hear:  NOR THE ROOF SO LONG AS IT HAS A PARAPET TEN HANDBREADTHS HIGH.