(Rav Nachman): If witnesses say that the document they signed was Emanah, or that they signed a sale document about which they heard a Moda'ah from the seller, they are not believed.

(Mar bar Rav Ashi): They are not believed to say that what they signed was Emanah, but they are believed to say that they signed a sale document about which they heard a Moda'ah (Tosfos - only if we cannot validate the document without them; Rashbam - even if we can validate it without them).

Question: What is the difference between the cases?

Answer: One may not write and give a document of Emanah, so they are not believed to incriminate themselves. One may sign a document after hearing a Moda'ah.

(Mishnah): A man does not get a Chazakah in his wife's property...

Objection: This is obvious! He is entitled to eat the Peros, so this is no proof that he owns the land itself!

Answer: The Chidush is, even if he wrote a document saying 'I have no claim to your property' (and has no rights to the Peros), he has no Chazakah.

Question: Such a document is meaningless!

(Beraisa): If Levi wrote to Yehudah 'I have no claim to this field', 'I have no business in it', or 'my hand is removed from it', this has no effect.

Answer (d'Vei R. Yanai): Our Mishnah discusses one who wrote this during Eirusin, before the Nisu'in, like Rav Kahana taught;

(Rav Kahana): One can stipulate (Tosfos - even with a weak expression of refusal) not to inherit an inheritance that is only mid'Rabanan (for Rava's reason);

(Rava): If an enactment was made to benefit a person, in a case like this, he can say 'I do not want the enactment.'

Question: To which case does Rava refer?

Answer: He refers to Rav Huna's law;

(Rav Huna): A woman can tell her husband 'you need not feed me, and I will not work for you' (because it was enacted for her benefit that he feed her and she will work for him).

Inference: The Mishnah said that a man does not get a Chazakah in his wife's property, but if he can prove (through witnesses) that she sold it to him, he gets it!

Question: Why can't she say 'I never meant to sell it. I merely wanted to please my husband'?

(Mishnah): If Reuven bought from Shimon a field designated to pay the Kesuvah of Shimon's wife, and then he bought it from her, the latter sale is void (she does not lose rights to collect her Kesuvah from it). She can say 'I merely wanted to please my husband.'

Answer: Rabah bar Rav Huna explained, that applies only to three types of fields: a field that he wrote in her Kesuvah that she has a lien to collect from it; a field that he made (in front of witnesses) an Apotiki from which to collect her Kesuvah; and a field that she brought into the marriage as Tzon Barzel (he must return to her its initial value when he pays her Kesuvah).