יב דתני לוי אמו פעמים פוטרת צרתה ופעמים אינה פוטרת צרתה כיצד היתה אמו נשואת אביו ונשאת לאחיו מאביו ומת זו היא אמו שאין פוטרת צרתה
12 died without issue, and she thus came into levirate relationship with her son;<span class="x" onmousemove="('comment',' Lit., 'and she fell before her son', who is the paternal brother of her deceased husband, Reuben. ');"><sup>33</sup></span> and since she is forbidden to him,<span class="x" onmousemove="('comment',' As his mother. ');"><sup>34</sup></span> her rival also is likewise forbidden!<span class="x" onmousemove="('comment',' Why then was not this case included in our Mishnah? ');"><sup>35</sup></span> — The other replied: [The author of our Mishnah] deals only with lawful brotherhood but not with brotherhood which is due to a forbidden act. Levi nevertheless<span class="x" onmousemove="('comment',' Despite Rabbi's abusive reply, supra 9a. ');"><sup>36</sup></span> inserted it<span class="x" onmousemove="('comment',' [H] lit., 'examined it', i.e., revised our Mishnah and added the case under discussion. [Levi drew up a collection of teachings like those of R. Hiyya and R. Oshaia, v. B.B., Sonc. ed. p. 216]. ');"><sup>37</sup></span> in his Mishnah. For Levi taught: One's mother sometimes exempts her rival<span class="x" onmousemove="('comment',' From halizah and the levirate marriage. ');"><sup>38</sup></span> and sometimes she does not exempt her. If his mother, for instance,<span class="x" onmousemove="('comment',' Lit., 'how so?'. ');"><sup>39</sup></span> was lawfully married to his father, and then she was married<span class="x" onmousemove="('comment',' Unlawfully. ');"><sup>40</sup></span> to his paternal brother<span class="x" onmousemove="('comment',' Which is a marriage forbidden under the penalty of kareth and is, therefore, illegal and invalid. ');"><sup>41</sup></span> who subsequently died, such a mother does not exempt her rival.<span class="x" onmousemove="('comment',' The marriage having been invalid, the woman is not regarded as his brother's wife. ');"><sup>42</sup></span>