Reference for Bava Metzia 133:12

אמר מר בריה דרב יוסף משמיה דרבא הא משכנתא באתרא דמסלקי אכל שיעור זוזי מסלקינן ליה

But it is not so: neither [the law of] 'overreaching' refutes him, nor [that of] a 'barren woman' supports him. [Thus: the law of] overreaching does not refute him, for he [the victim did not know that he was defrauded at all, that he should forego it.<span class="x" onmousemove="('comment',' So that there is no renunciation at all, even in error, and therefore it must be returned. ');">¹²</span>

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