Reference for Nedarim 140:2

אימא ה"מ בנדרי' שלא נראו לארוס אבל בנדרים שנראו לארוס לא מצי מיפר אב

just as those made before the first betrothal, the father can annul alone, so also those made before the second betrothal, the father can annul alone. But perhaps this is only in the case of vows which were unknown to the arus,<span class="x" onmousemove="('comment',' Lit., 'which were not seen by the arus'. I.e., the first arus died before becoming aware of them. ');">²</span>

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