Responsa for Bava Batra 114:4
רב פפא אמר אידי ואידי בחצר השותפין ואיכא דקפדי ואיכא דלא קפדי גבי ממונא לקולא גבי איסורא לחומרא
Rabina said: Indeed we assume in all cases that the joint owners are not particular,<span class="x" onmousemove="('comment',' And therefore by rights the vow would not be broken by the act of standing in the courtyard. ');"><sup>7</sup></span> and the rule [regarding vows] is based on the opinion of R. Eliezer, as it has been taught: R. Eliezer says, One who has vowed to receive no benefit from another is forbidden to take even a makeweight from him.<span class="x" onmousemove="('comment',' If the man who has made the vow buys 100 nuts from the other, and he gives him one or two over, as to all customers, he may not accept them. Similarly, by standing in the courtyard the man who has made the vow receives a certain benefit from the other, even though the latter claims (as against him) no ownership in the courtyard. ');"><sup>8</sup></span>