Reference for Eruvin 68:4
<big><strong>מתני׳</strong></big> נתנו בראש הקנה או בראש הקונדס בזמן שהוא תלוש ונעוץ אפילו גבוה ק' אמה הרי זה עירוב:
WAS PUT ON THE TOP OF A REED OR ON THE TOP OF A POLE, PROVIDED<span class="x" onmousemove="('comment',' Lit., 'at the time'.');"><sup>11</sup></span> IT HAD BEEN UPROOTED AND THEN INSERTED [IN THE GROUND, EVEN THOUGH IT WAS A HUNDRED CUBITS HIGH, THE ERUB IS EFFECTIVE.<span class="x" onmousemove="('comment',' If it rested on a platform of no less than four handbreadths by four, that was attached to the top of the reed or the pole.' Such a platform, though it conforms to the size of a private domain, cannot be regarded as a private domain proper on account of the base on which It rests which is narrower than the prescribed size of four handbreadths.');"><sup>12</sup></span> <big><b>GEMARA: </b></big>R'Adda B'Mattena pointed out to Raba the following incongruity: [From our Mishnah it appears that] only<span class="x" onmousemove="('comment',' Lit., 'yes'.');"><sup>13</sup></span> if IT HAD BEEN UPROOTED AND THEN INSERTED [IN THE GROUND is the 'erub effective, but if it was] not first uprooted and then inserted [in the ground the 'erub would] not [have been effective].<span class="x" onmousemove="('comment',' Obviously because the 'erub could not be removed from its place on account of the prohibition of making use of a growing plant.');"><sup>14</sup></span>