Ketubot 164
מהו דתימא מצוה דרמא רחמנא עליה עבדה והשתא תיקום עליה באיסור אשת אח קא משמע לן
What might you have thought? Since he has already performed the commandment that God imposed on him she shall again become prohibited to him by being his brother’s wife, hence it teaches us [that he may remarry her].
ואימא הכי נמי אמר קרא (דברים כה, ה) ולקחה לו לאשה כיון שלקחה נעשית כאשתו:
But might it not be suggested that the law is so indeed? The verse stated, “And take her to him to wife,” (Deuteronomy 25:5) once he has taken her she becomes his wife [in all respects].
מהו דתימא התם הוא דלא כתב לה דקנאי ודקנינא אבל הכא דכתב לה דקנאי ודקנינא אימא סמכה דעתה קמ"ל:
What might you have said? [That the restriction mentioned applies only] in the former case because the levir does not write [in the ketubah] “That which I acquired and that which I will acquire,” but here, where he does write, ‘That which I acquired and that which I will acquire,” she relies upon this guarantee, hence it needed to teach us this in both cases.
החזירה הרי היא ככל הנשים ואין לה אלא כתובתה: החזירה מאי קא משמע לן תנינא המגרש את האשה ומחזירה על מנת כתובה ראשונה מחזירה
If he remarried her she is the same as all other wives, and is entitled only to her ketubah. If he remarried her! What does this teach us? Have we not learned: If a man divorced his wife and then remarried her, his second marriage is contracted on the terms of her first ketubah?
מהו דתימא אשתו הוא דאיהו כתב לה כתובה מיניה אבל יבמתו דלא איהו כתב לה היכא דגרשה ואהדרה אימא כתובתה מיניה קא משמע לן:
What might you have thought? [This is true of] his wife, since it was he himself who wrote the ketubah; but the case of his yevamah, since it was not he who wrote the ketubah for her, when he divorced her and remarried her the ketubah should come from him, therefore it taught [that in this case also she is entitled only to the first ketubah].
אמר רב יהודה בראשונה היו כותבין לבתולה מאתים ולאלמנה מנה והיו מזקינין ולא היו נושאין נשים עד שבא שמעון בן שטח ותיקן כל נכסיו אחראין לכתובתה:
Rav Judah said: At first they used to write for a virgin’s ketubah two hundred zuz and for a widow a maneh, and consequently they grew old and could not take any wives, until Shimon b. Shetah came and ordained that all the property of a husband is pledged for the ketubah of his wife.
תניא נמי הכי בראשונה היו כותבין לבתולה מאתים ולאלמנה מנה והיו מזקינין ולא היו נושאין נשים התקינו שיהיו מניחין אותה בבית אביה ועדיין כשהוא כועס עליה אומר לה לכי אצל כתובתיך
It was also taught thus: At first they used to write for a virgin’s ketubah two hundred zuz and for a widow a maneh, and consequently they grew old and could not take any wives. So they established that he should deposit the money in her father’s house. Still whenever he would get angry with her he used to tell her, “Go to your ketubah.” They ordained that the amount of the ketubah was to be deposited in the house of her father-in-law.
ועדיין כשכועס עליה אומר לה טלי כתובתיך וצאי עד שבא שמעון בן שטח ותיקן שיהא כותב לה כל נכסי אחראין לכתובתה:
Still, whenever the husband would get angry with his wife he would say to her, “Take your kethubah and go.” Until Shimon b. Shetah came and ordained that all the property of a husband is pledged for the ketubah of his wife.