Reference for Eruvin 122:2
מיתיבי אמר להן ר"ע אי אתם מודים לי בנותן את עירובו במערה שאין לו ממקום עירובו אלא אלפים אמה אמרו לו אימתי בזמן שאין בה דיורין הא באין בה דיורין מודו ליה
If, however, he deposited his 'erub in a deserted town<span class="x" onmousemove="('comment',' But did not himself spend the Sabbath in it.');"><sup>5</sup></span> he is allowed no more than a distance of two thousand cubits from the place of his 'erub.<span class="x" onmousemove="('comment',' Because, in the case of the deposit of an 'erub, as explained supra, the Rabbis draw a distinction between all inhabited town and a deserted one. Only in the former case is the entire area of the town regarded as no bigger than four cubits. R. Akiba, however, (cf. supra n. 9) differs from their view and regards even an inhabited town as they do a deserted one.');"><sup>6</sup></span> R'Eleazar laid down: Whether a man spent the Sabbath in a town or deposited in it his 'erub he is permitted<span class="x" onmousemove="('comment',' According to the Rabbis.');"><sup>7</sup></span> to walk through the whole of it and two thousand cubits beyond.