Bava Batra

Now, if [the dispute has reference] to field and tree,  why does he reverse [his view]?  Consequently  Rabbah said: The dispute  [has reference] to cistern and dove-cote, but [in the case of] field and tree both agree that they and their contents are subject to the law of Me'ilah. On what principle do they  differ when the cistern and dove-cote are empty, and on what principle do they differ when the cistern and dove-cote are full? — When [the cistern and dove-cote are] empty, the dispute is analogous to that of R. Meir and the Rabbis. For the first Tanna is of the same opinion as the Rabbis who said no one can hand over possession of a thing that does not exist,  while R. Eleazar b. Simeon is of the same opinion as R. Meir who said  that one can hand over possession of a thing that does not exist.  [But] say! where has R. Meir been heard [to express his view? Only in the case], for example, as that of fruits of a palm-tree, because they generally come up, but [as to] these,  who can assert that they will come?  — Raba said: It is possible  when water runs through his [own] courtyard into the cistern and when doves come through his dove-cote into the [dedicated] dove-cote. And in what case do they differ when [the cistern and dove-cote are] full? — Raba said: For example. when he dedicated a cistern without mentioning its contents; and R. Eleazar b. Simeon holds the same opinion as his father who said: We may infer the law concerning sacred property from the ordinary law.  As [in the case of] ordinary  law one can Say: 'I sold you a cistern, I did not sell you water so [in the case of] the law concerning sacred things [one can say]: 'I dedicated the cistern, I did not dedicate the water'.  But [can it be said that in] the ordinary law [the water is] not [implicitly sold]? Surely we learnt: He who sold a cistern has also sold its water!  Raba replied: This Mishnah represents an individual opinion;  for it has been taught: He who sold a cistern has not sold its water. R. Nathan said: He who sold a cistern has sold its water.