Talmud for Eruvin 139:14

אחד שלא עירב נותן רשותו לאחד שעירב לאביי דאיתיה וקמ"ל דאין צריך לבטל רשות לכל אחד ואחד לרבה דהוה ומית ולא גזור זימנין דאיתיה

And<span class="x" onmousemove="('comment',' Cf. supra n. 10.');">⁴⁴</span> 'two tenants who joined in an 'erub may present their shares to the one who did not join in their 'erub'. Is not this obvious?<span class="x" onmousemove="('comment',' Since the latter may well renounce his share in their favour, on account of the 'erub in which they have joined. no preventive measures against the possibility that one tenant might renounce his share in favour of two, could have been required. Now, since It was already stated in the first clause that one tenant may renounce, what need was there to mention also two?');">⁴⁵</span> - It might have been presumed<span class="x" onmousemove="('comment',' Since the first clause deals with a renunciation in favour of those who did join in an 'erub.');">⁴⁶</span> that the tenant, since he did not join in the 'erub, should be penalized,<span class="x" onmousemove="('comment',' And no renunciation in his favour should be permissible.');">⁴⁷</span>

Jerusalem Talmud Eruvin