Reference for Yevamot 238:13
<big><strong>גמ׳</strong></big> תנא לזו עדים ובנים ולזו לא עדים ולא בנים שתיהן מותרות
ON ACCOUNT OF THE HUSBAND OF THE LATTER,<span class="x" onmousemove="('comment',' Who might, in fact, he alive and with whom halizah or levirate marriage must he performed. A woman is eligible to tender evidence on the death of her husband in so far only as to enable herself to marry again. She is ineligible, however, to give evidence enabling her sister-in-law to marry again. ');"><sup>33</sup></span> AND THE LATTER IS FORBIDDEN<span class="x" onmousemove="('comment',' To marry again. ');"><sup>34</sup></span> ON ACCOUNT OF THE HUSBAND OF THE FORMER.<span class="x" onmousemove="('comment',' Who might, in fact, he alive and with whom halizah or levirate marriage must he performed. A woman is eligible to tender evidence on the death of her husband in so far only as to enable herself to marry again. She is ineligible, however, to give evidence enabling her sister-in-law to marry again. ');"><sup>33</sup></span>