Reference for Shabbat 14:8
זימנין משני לה שאני צרור וחפץ דמיהדר ואתי זימנין משני לה בכותל דלית ביה חור ממאי מדקתני רישא זרק למעלה מי' טפחים כזורק באויר ואי ס"ד בכותל דאית ביה חור אמאי כזורק באויר הא נח בחור
sometimes he answered him: The reference must be to a wall not possessing a cavity. — How do you know it? — Because the first clause states: If one throws above ten handbreadths, it is as though he throws it into the air. Now if you imagine that this refers to a wall with a cavity, why is it as though he throws It into the air; surely it came to rest in the cavity?<span class="x" onmousemove="('comment',' Which, if four handbreadths square, is private ground. ');"><sup>13</sup></span> And should you answer, Our Mishnah [refers to a cavity] that is not four square, — surely did not Rab Judah say in R. Hiyya's name: If one throws [an article] above ten handbreadths and it goes and alights in a cavity of any size,<span class="x" onmousemove="('comment',' I.e., less than four square. ');"><sup>14</sup></span>