Reference for Eruvin 123:15
רבי אליעזר בן יעקב אומר לעולם אינו אוסר עד שיהו שני ישראלים אוסרים זה על זה
But if only one Israelite<span class="x" onmousemove="('comment',' Who, by virtue of his tenancy of a house, is entitled to the use of the courtyard.');"><sup>32</sup></span> was a tenant there, he<span class="x" onmousemove="('comment',' Since the courtyard (cf. prev. n.) is deemed to be his domain.');"><sup>33</sup></span> does impose restrictions;<span class="x" onmousemove="('comment',' On the carrying of objects by other Israelites from the houses into the courtyard and vice versa.');"><sup>34</sup></span> so R'Meir.<span class="x" onmousemove="('comment',' The last three words are absent from the Tosef.');"><sup>35</sup></span> R'Eliezer B'Jacob ruled: No restrictions are ever imposed<span class="x" onmousemove="('comment',' On account of the heathen's tenancy.');"><sup>36</sup></span> unless there are also two Israelite tenants<span class="x" onmousemove="('comment',' Occupying two houses in that courtyard.');"><sup>37</sup></span> who impose restrictions upon one another.<span class="x" onmousemove="('comment',' Tosef. 'Er. V. As the heathen's share is distinct from theirs (a heathen's tenancy, as explained supra, having been given validity in such circumstances) they, by virtue of their shares in the courtyard, impose restrictions on the movements of objects from the heathen's house into the courtyard while he, by virtue of his share, despite the 'erub in which the two Israelites may have joined, imposes restrictions on the movements of objects from their houses into the courtyard.');"><sup>38</sup></span>