Study Yevamot folio 18A with parallel Hebrew-English text, traditional commentary, and modern study tools. Free access to Babylonian Talmud online.
Text Excerpt
הוה אמינא מחיים, אבל לאחר מיתה — פקעה לה זיקה, קא משמע לן דזיקה בכדי לא פקעה. לימא מסייע ליה: יבמתו שמתה — מותר באחותה. באחותה אין, באמה לא!
I would say that the levirate bond applies as long as the yevama requiring levirate marriage is alive but that after her death the bond was terminated. In other words, after the yevama died any relationship between the two dissolved. This comes to teach us that the bond is not terminated without cause but instead requires an actual act, such as ḥalitza or levirate marriage. Until one of these acts is performed, the bond remains in place. Let us say that it supports Rav Yehuda’s opinion from that which was taught: If his yevama dies, he is permitted to marry her sister. From here the Talmud deduces: Her sister, yes; her mother, no, in accordance with the opinion of Rav Yehuda.
הוא הדין דאפילו באמה, ואיידי דתנא רישא: אשתו שמתה — מותר באחותה, דוקא באחותה, אבל באמה לא, דהויא לה איסורא דאורייתא — תנא נמי סיפא מותר באחותה.
The Talmud rejects this: The same is true, that even her mother is permitted. And this language was used only since he taught in the first clause of the baraita: If his wife dies he is permitted to take her sister; specifically her sister but not her mother, as she is forbidden by Torah law. Therefore, he also taught in the latter clause that he is permitted to marry her sister.
מתיב רב הונא בר חייא: עשה בה מאמר ומת — שניה חולצת ולא מתייבמת. טעמא דעבד בה מאמר, הא לא עבד בה מאמר — שניה נמי יבומי מייבמה, ואי אמרת יש זיקה, הויא לה צרת אשת אחיו שלא היה בעולמו בזיקה!
Rav Huna bar Ḥiyya raised an objection to this from the Mishnah: If he performed levirate betrothal with her and then died, the second woman performs ḥalitza and may not enter into levirate marriage. This implies that the reason is specifically that he performed levirate betrothal with her. Had the brother not performed levirate betrothal with her, the second woman would also be permitted to enter into levirate marriage. And if you say that the levirate bond is substantial, then she would be considered a rival wife of the wife of a brother with whom the third brother did not coexist by that bond. Since the wife of a brother with whom he did not coexist is prohibited from entering into levirate marriage, her rival wife would likewise be forbidden from doing so.