Reference for Bava Batra 133:9
ואיכא דאמרי
Raba further said: If a man sells another the shore<span class="x" onmousemove="('comment',' For the sake of the sand. Lit., 'a sandy field'. ');"><sup>15</sup></span> of a river and its bed,<span class="x" onmousemove="('comment',' For gold and silver washings, or, according to others, for the fish. ');"><sup>16</sup></span> if the purchaser takes possession of the shore he does not thereby acquire ownership of the bed, and if he takes possession of the bed he does not thereby acquire ownership of the shore.<span class="x" onmousemove="('comment',' Because they are used for different purposes and have different names. ');"><sup>17</sup></span> Is that so? Has not Samuel laid down that if a man sells another ten fields in ten different provinces, as soon as the purchaser has taken formal possession of one<span class="x" onmousemove="('comment',' By digging a little or some similar action. ');"><sup>18</sup></span> he becomes owner of all? — The reason there is that the earth is all one stretch<span class="x" onmousemove="('comment',' Lit., 'the block of the land ');"><sup>19</sup></span> and all [the properties] are utilised in the same way. Here, however, one thing is for one purpose and the other for another. According to another version,