Maseches Kesubos, Chapter 11, Mishnah 3. This mishnah follows on the opinion of Rabbi Shimon taught in the previous mishnah, and it deals with a widow who has already taken some action regarding her kesubah, and the law of her selling from that point onward.
The text of the mishnah and its explanation:
"Machrah kesubasah o miktzasah" - she sold her kesubah in its entirety, or part of it.
"Mishkenah kesubasah o miktzasah" - she gave the kesubah, in whole or in part, as collateral.
"Nasnah kesubasah l'acher o miktzasah" - she gave the kesubah, in whole or in part, as a gift to another person.
In each of these cases the mishnah rules: "Lo timkor es hashe'ar ela b'veis din" - she may sell the remainder of the kesubah only in beis din. And even the maneh that comes from the marriage itself, regarding which one opinion among the Rishonim was cited in the previous mishnah that she may sell it even outside of beis din - once she has sold, pledged or given, she sells only in beis din.
The basis of Rabbi Shimon's position:
The permission to sell outside of beis din rests on the fact that the sale is also being made for the sake of her support. Rabbi Shimon holds that once she has sold her kesubah or part of it, she no longer receives support; and once there is no support, the reason permitting her to sell outside of beis din no longer applies. Therefore, even if only part of the kesubah was sold, pledged or given as a gift, she sells the remainder only in beis din.
The position of the Chachamim:
The Chachamim hold that she does not forfeit her support because she sold or gave away part of the kesubah; rather, she continues to receive support until she sells the entire kesubah. For this reason the Chachamim say: "Mocheres hi afilu arba'ah v'chamishah pe'amim" - she may sell even four or five times, in varying amounts, and she sells for support outside of beis din. Only after she has sold and collected the entire kesubah does her support cease.
"U'mezonos macharti" - sound advice:
The mishnah adds that when she sells the land of the estate for the sake of her support, she should write in the bill of sale that the sale is being made for support, and distinguish between what was sold for support and what was sold for the kesubah. The Gemara explains that this is not an absolute law but sound advice: if she does not specify what she sold for support and what she sold for the kesubah, people will assume that she sold all the property for her support alone, and she will get a reputation as a glutton who spends a great deal of money on her food, and men will not want to marry her. She should therefore specify that not everything was sold for support, but part of it for the kesubah, so that a mistaken impression not form about her.
The law of a divorced woman:
The final clause of the mishnah: "U'gerushah lo timkor ela b'veis din". A divorced woman does not collect support, only her kesubah, and therefore neither of the two reasons to permit selling outside of beis din applies to her:
From the standpoint of the disgrace: according to the opinion that a man does not want his wife to be disgraced in beis din - with a divorced woman this does not concern him, since he has already divorced her.
From the standpoint of support: according to the opinion that the permission to sell outside of beis din stems from the collection of support - a divorced woman has no support at all.
Therefore a divorced woman sells only in beis din.
In summary: in this mishnah Rabbi Shimon and the Chachamim disagree about a widow who sold, pledged or gave away her kesubah or part of it: according to Rabbi Shimon her support has lapsed and she sells the remainder only in beis din, while according to the Chachamim her support continues and she may sell even four or five times outside of beis din, until the entire kesubah has been collected. We also learned the sound advice to specify in the document what was sold for support, so that she not acquire a bad reputation, and the law of a divorced woman, who sells only in beis din.