Reference for Eruvin 121:7
מאן דתני אנשי לא משתבש דמוקים לה בנותן ומאן דתני אין אנשי לא משתבש דמוקים לה במודד
and that a clause is missing [from the Mishnah] which should properly read thus: The people of a large town may walk through the whole of a small town<span class="x" onmousemove="('comment',' Where the latter was situated entirely within the Sabbath limit of the former. If, for instance, the distance between the two towns was one thousand cubits and the smaller did not cover more than one thousand cubits the people of the larger town may walk through the whole of the smaller (which being within their Sabbath limit, is regarded as no bigger than four cubits) and another thousand cubits or more beyond it to complete their two thousand cubits Sabbath limit.');"><sup>19</sup></span> but the people of the small town may not walk through the whole of the large town.<span class="x" onmousemove="('comment',' Since the larger town (cf. prev. n.) is not entirely situated within their Sabbath limit. They may, therefore, walk the distance of a thousand cubits between the two towns and another thousand cubits, to complete their Sabbath limit, within the larger town itself, but no further.');"><sup>20</sup></span> This, however, applies only to a case where the Sabbath limit was being measured, but if a man stayed in a larger town and deposited his 'erub in a smaller town<span class="x" onmousemove="('comment',' That was situated within the Sabbath limit of his own town.');"><sup>21</sup></span> or if he stayed in a small town and deposited his 'erub in a large town<span class="x" onmousemove="('comment',' That was situated within the Sabbath limit of his own town.');"><sup>21</sup></span>