Reference for Eruvin 141:11

אמר אביי מת נכרי בשבת מאי כלך אצל יפות איכא

Said Ulla: What is Beth Hillel's reason?<span class="x" onmousemove="('comment',' For allowing renunciation on the Sabbath.');">²¹</span> The case of renunciation is on a par with that of saying,<span class="x" onmousemove="('comment',' Lit., 'it is made as (if he) says' to a person whom he found in his field setting aside terumah from a certain kind of produce on his behalf without his previous consent.');">²²</span> 'You should have gone to the better kind'.<span class="x" onmousemove="('comment',' B.M. 22a. The terumah is valid if there was a better kind in the field; because the owner, by his present consent, is assumed retrospectively to have appointed the person as his agent. Similarly in the case of renunciation: The tenant's present act of renunciation is taken as an indication of his retrospective desire to join with the other tenants in their 'erub and that his failing to do so was due to mere forgetfulness.');">²³</span>

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