Reference for Yevamot 33:12
עשה בה מאמר ומת שניה חולצת ולא מתייבמת:
TOOK IN LEVIRATE MARRIAGE HIS DECEASED BROTHERS WIFE AND THEN DIED HIMSELF, THE FIRST WOMAN<span class="x" onmousemove="('comment',' The widow of the first deceased brother who is now also the widow of the second brother. ');"><sup>44</sup></span> IS EXEMPT<span class="x" onmousemove="('comment',' From levirate marriage with the third brother. ');"><sup>45</sup></span> AS 'THE WIFE OF HIS BROTHER WHO WAS NOT HIS CONTEMPORARY', AND THE SECOND<span class="x" onmousemove="('comment',' Her rival, the widow of the second brother, who in ordinary circumstances would have been subject to levirate marriage with the third brother since he was a contemporary of her husband. ');"><sup>46</sup></span> [IS EXEMPT]<span class="x" onmousemove="('comment',' From levirate marriage with the third brother. ');"><sup>45</sup></span>