Gemara

Question: If a wife was Overes Al Das (deviated from the modest ways of Bnos Yisrael), does she forfeit her Kesuvah even if she was not warned?

Since she acted immodestly, no warning is needed. Or, perhaps we must warn her. Maybe she will correct her behavior.

Answer (R. Chanina of Sura - Mishnah): Beis Din can warn the wife of a man who became deaf or insane, or was imprisoned.

She may not drink. She is warned, so that if she is secluded, she forfeits her Kesuvah. This teaches that she does not forfeit her Kesuvah without warning.

Kesuvos 72a (Mishnah): A woman is divorced without a Kesuvah for Overes Al Das.

Transgressing Das Moshe (Torah law) is feeding to him untithed food, having Bi'ah with him when she is Nidah, not separating Chalah, or vowing and transgressing her vows.

Question: What is the case of feeding to him untithed food?

If he knows that it is untithed, he should not eat it! If he does not know that it is untithed, how does he know that she fed him untithed food?

Answer: She said that Ploni separated the tithes. He asked Ploni, and found that she lied.

Question: How does he find out that she had Bi'ah with him when she was Nidah?

Answer #1: She saw a Kesem (blood stain), and said that Ploni ruled that it does not make her Nidah. He asked Ploni, and found that she lied.

Answer #2: She was established to be a Nidah among her neighbors.

The case of not separating Chalah is when she said that Ploni the kneader separated the Chalah. Her husband asked Ploni, and found that she lied.

Rishonim

Rif and Rosh (Kesuvos 32b and 7:9): We conclude that Overes Al Das forfeits her Kesuvah only if she was warned. The Yerushalmi says that if she was not warned, he divorces her and pays a Kesuvah.

(Rosh, ibid.): What forced the Gemara to say that he transgressed? Perhaps she tried to feed to him Isur, and he realized this and did not eat, but he wants to divorce her lest another time he will not know to refrain! It seems that in this case he could not divorce her for free (without a Kesuvah), for she could say that she was joking, and she would have told him before he ate. We conclude that she said that Ploni separated the tithes (or Chalah, or was Metaher her stain). He asked Ploni, and found that she lied. The Yerushalmi says that Ploni is not believed to make her lose her Kesuvah when she contradicts him. To make someone lose money we need two witnesses. I.e., they say that Ploni was not in the city at the time she says (that he separated or was Metaher). Alternatively, she denies that she told her husband that Ploni separated or was Metaher, and two witnesses refute her.

Ran (DH Gemara): The Ra'avad says that we did not say that she admitted to feeding to him Isur because a person cannot establish himself to be a Rasha. This is wrong. A person's admission is like 100 witnesses; she is believed to forfeit her Kesuvah. The Gemara did not establish the case like this because it is uncommon.

Ramban (cited in Rosh Shevu'os 4:17 and Ran, ibid.): I received the Halachah that in every case of Ed mi'Pi Ed, i.e. David testified based on what Levi told him, if Levi came and said differently, David is not believed to contradict him. A proof is from Kesuvos (72a). If a woman said that Ploni was Metaher her stain, and he contradicts her, she is not believed.

Rosh (ibid.): This is reasonable.

Question (Ran): The Yerushalmi says 'all of these are through witnesses.' Perhaps the Ramban explains that this does not include when she cites Ploni. The Rashba explains like the simple understanding of the Yerushalmi.

Rambam (Hilchos Ishus 24:11): Das Moshe is going out in the market with uncovered hair, taking vows or oaths and transgressing them, having Bi'ah with him when she is Nidah, not separating Chalah, or feeding to him Isur. The case is, she said that Ploni tithed produce or separated Chalah or was Metaher her stain, and after her husband ate or had Bi'ah with her he asked Ploni and Ploni said that he did not. The same applies if she was established to be a Nidah among her neighbors, and she told him that she is Tehorah and they had Bi'ah.

Rambam (14): Overes Al Das forfeits her Kesuvah only through warning and witnesses. If her husband saw her transgress and warned her without witnesses and she transgressed again, and she says that she did not transgress at all or was not warned, if he wants to divorce her he must pay a Kesuvah after she swears that she did not transgress.

Magid Mishneh: This is like any claim of money. He seeks to make her lose her Kesuvah, so he must bring proof. If he knows that she was Overes Al Das, he can make her swear. If he is unsure he cannot make her swear, for she holds the Kesuvah, and we do not establish people to be Resha'im (without proof). After paying her, he can make her swear Heses.

Beis Shmuel (EH 115:18): If she had Bi'ah with him while Nidah, she herself also transgressed. She is a Rasha, and may not swear. When she made only him transgress, she is not suspected to swear falsely.

Hagahos Maimoniyos (3): A case occurred in which Leah became friendly with Do'eg, and Do'eg threatened to kill her husband. Surely he may divorce her against her will, for she was Overes Al Das (for speaking with men). However, if she was not warned he must pay her Kesuvah.

Poskim

Shulchan Aruch (EH 115:1): If a wife was Overes Al Das Moshe, she leaves without a Kesuvah. E.g. she said that Ploni tithed this produce or permitted this piece or was Metaher this blood, and she was found to be lying. This is only if two witnesses contradicted her, e.g. they testify that at the time that she says that Ploni fixed the produce, Ploni was not in the city.

Chelkas Mechokek (4): The Rosh in Shevu'os and the Ran bring the Ramban's opinion that she is not believed to contradict Ploni. It seems that the Rambam agrees. Why did the Shulchan Aruch omit this opinion? She is not believed to contradict women neighbors who saw her wear Nidah clothing. Surely a Chacham should be believed! In Kesuvos, the Rosh said 'Ploni fixed this produce', i.e. I saw him. This is not like Ed mi'Pi Ed, therefore he is not believed to contradict her. When she says that Ploni was Metaher her stain, she herself does not know, therefore Ploni is believed. The Shulchan Aruch must discuss when she says that she herself knows that Ploni fixed the produce. However, Kitzur Piskei ha'Rosh connotes otherwise.

Beis Shmuel (4): The Beis Yosef (YD 183 DH b'Perek) says that the Chacham is believed that she is Nidah, but not to make her lose her Kesuvah, and the Rosh and Rashba agree with this. However, it seems that the Rambam believes the Chacham even regarding the Kesuvah.

Shulchan Aruch (ibid.): We also need witnesses that she told her husband that it is permitted, and that he relied on her and ate. If there are no witnesses and she denies it, she is believed.

Chelkas Mechokek (3): It is not enough to contradict her about one matter. Even if we find that she lied about Ploni fixing the produce, she can say that she told her husband before he ate (unless witnesses say otherwise).

Beis Shmuel (5): The Rosh connotes that it suffices for witnesses to contradict her about one matter.

Shulchan Aruch (2): If she was established to be a Nidah among her neighbors, i.e. they saw her wearing Nidah clothing, and she told him that she is Tehorah and they had Bi'ah, she leaves without a Kesuvah.

Chelkas Mechokek (4): We must say that she admits that they had Bi'ah, or witnesses saw the actual Bi'ah. Witnesses of seclusion are not enough, for perhaps she told him before they had Bi'ah.

Beis Shmuel (6): The Chelkas Mechokek says that if she admits that they had Bi'ah, she is not believed to say that she was Tehorah. A Migo (she could have denied that she had Bi'ah) is not believed against neighbors who saw her wear Nidah clothing, which is like testimony. Sometimes, a woman is believed to say that she was Tehorah, but wore Nidah clothing for a special reason. The Levush says that even then he divorces her for free, for people will suspect that he was Bo'el Nidah. This is wrong. She may be divorced for free for making him transgress, not for besmirching his reputation.

Rema (ibid.): If she became an apostate and repented, she is not Overes Al Das. She forfeits her Kesuvah only after warning.

Chelkas Mechokek (16): Capital cases require warning at the time of the transgression. This is not required here, but she must be warned that she will forfeit her Kesuvah.

Beis Shmuel (17): Shiltei ha'Giborim says that it suffices to warn her not to act indecently. We learn from warning a Sotah. It suffices to warn her not to be secluded; he need not say that she will forfeit her Kesuvah. Darchei Moshe cites Maharam, the Rashba and Rosh to say that she must be warned about losing her Kesuvah; one can dispel the proof from there. Rashi (Sotah 25a) says that the Gemara asked about warning for Das Yehudis. Das Moshe does not need warning, for she already caused him to transgress.

Beis Shmuel (8): If she willingly became an apostate, she is forbidden to him, for perhaps she was Mezanah. Even though he is unsure whether or not she was Mezanah, and perhaps he is not exempt from paying her Kesuvah, since she caused the Safek he need not pay.