Reference for Eruvin 123:7

מ"ט אילימא משום דסבר דלמא אתי לאחזוקי ברשותו הניחא למ"ד שכירות בריאה בעינן

while R'Meir holds that, since it may sometimes happen that one Israelite also should live with a heathen, the Rabbis have laid down: No 'erub is effective where a heathen lives in the same courtyard, nor is the renunciation of one's right<span class="x" onmousemove="('comment',' To a share.');">¹⁴</span> effective where a heathen is concerned<span class="x" onmousemove="('comment',' Lit., 'in the place of', i.e., a heathen's renunciation of his right to his share in the common courtyard has no validity.');">¹⁵</span> unless that right has been let; but a heathen would not let his right.<span class="x" onmousemove="('comment',' As the Israelite would in consequence be subjected every Sabbath to much inconvenience he would naturally move out of that courtyard at the earliest possible opportunity and, indirectly, he would thereby be saved from the evil influence of the heathen's questionable mode of life.');">¹⁶</span>

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