Reference for Eruvin 103:7
ר"מ אומר כל שהוא יכול לערב ולא עירב הרי זה חמר גמל:
R'MEIR RULED: WHOSOEVER IS ABLE TO PREPARE AN 'erub<span class="x" onmousemove="('comment',' As the man here spoken of was.');"><sup>15</sup></span> AND NEGLECTED TO DO IT<span class="x" onmousemove="('comment',' Sc. omitted to make a declaration that he wished to acquire the place in question as his Sabbath base. knd rnj');"><sup>16</sup></span> IS IN THE POSITION OF AN ASS-DRIVER AND A CAMEL-DRIVER.<span class="x" onmousemove="('comment',' (v. n. supra 35a) . Since it is uncertain whether he intended to acquire his Sabbath base (a) on the boundary line between the two Sabbath limits that separate the one town from the other or (b) in his own house where he remained when the Sabbath began, he must be restricted in his movements to the two thousand cubits between the house in which he stayed and the termination of the Sabbath limit of that town. He must not proceed beyond the Sabbath limit of the town in the direction of the other town since it is possible that he acquired his Sabbath base at (b) , and he must not move outside the town in the opposite direction, since it is possible that his Sabbath base had been acquired at (a) .');"><sup>17</sup></span>