Gemara

(Mishnah): If property fell to a Yevamah, Beis Shamai and Beis Hillel agree that she may sell it, and the sale is valid.

Question: If she died, what do we do with her Kesuvah and the property that enters and leaves the marriage with her?

Answer #1 (Beis Shamai): Her husband's heirs split it with her father's heirs;

Answer #2 (Beis Hillel): The property retains its status quo. The Kesuvah stays by the husband's heirs, and property that enters and leaves with her stays by her father's heirs.

Yevamos 38a - Question: Why do they argue only in the Seifa?

Answer #1 (Ula): In the Reisha, she fell to Yibum from Kidushin. In the Seifa, she fell from Nisu'in.

Ula holds that Zikah (of one who fell) from Kidushin is like Safek Kidushin, and Zikah from Nisu'in is like Safek Nisu'in.

Objection (Rabah): If so, rather than arguing about the property itself after she dies, they should argue about who eats the Peros during her lifetime!

Answer #2 (Rabah): In both cases she fell from Nisu'in. Zikah from Nisu'in makes Safek Nisu'in.

In the Reisha she is alive. She is Vadai (Kinyan ha'Guf is hers), and her husband is Safek (perhaps he receives Peros). A Safek cannot take from a Vadai. In the Seifa she died and both heirs come to inherit, so they divide.

Answer #3 (Abaye): In the Reisha, the property fell after she fell to Yibum. In the Seifa, it fell when she was still married.

(Regarding property that falls to her) Abaye holds that her husband's Yad (power to acquire) is like her Yad.

Objection (Rava): If the property fell to her when she was married, all agree that his Yad is stronger than hers!

Answer #4 (Rava): Rather, in both cases, the property fell after she fell to Yibum. In the Reisha, no Ma'amar was given. In the Seifa, a Ma'amar was given.

Rava holds that Beis Shamai hold that Ma'amar makes Vadai Kidushin (to exempt the Tzarah), and Safek Nisu'in (to split her property).

(Rav Papa): Scrutiny shows that the Mishnah is like Abaye, but there is a difficulty. 'Property that enters and leaves with her' connotes property which enters her husband's Reshus, and leaves to return to the father.

Question: Why does the Mishnah discuss who gets the property itself after her death? It could discuss who eats the Peros during her lifetime!

Kesuvos 83a (Mishnah): If a man wrote to his wife 'I have no claim or dealings in your property nor in its Peros', he does not eat the Peros in her lifetime.

(D'Vei R. Yanai): The case is, he wrote to his wife during Eirusin.

Question: Why doesn't the law apply even if he wrote after Nisu'in?

Answer #1 (Abaye): After Nisu'in, the husband's Yad (power of acquisition) is equal to his wife's Yad (in her property).

Answer #2 (Rava): His Yad is stronger than her Yad.

Abaye and Rava differ regarding a Shomeres Yavam.

Rishonim

Rif (Kesuvos 41b): After Nisu'in a man cannot waive his rights to his wife's property. Abaye says that this is because his Yad is like her Yad. Rava says that his Yad is stronger than hers. They argue about a Shomeres Yavam. If she dies, her husband inherits her. If her husband dies and she fell to Yibum, she does not take control of property that fell to her in her husband's lifetime. Rather, his Reshus is still with her; the Yavam's Yad is stronger than hers.

Ba'al ha'Ma'or (Yevamos 12a): Abaye holds that his Yad is like her Yad. Rashi says that this is according to Beis Hillel. This is wrong. The entire Sugya seeks to explain Beis Shamai! Here, the Rif does not comment on the Sugya. Perhaps he rules like Abaye, for Rav Papa favors him. However, this is not enough to overturn the Kelal that we follow Rava against Abaye. Rabanan rely on Rashi, who says that his hand is better when the husband is alive, and the Yavam's hand equals hers after the husband died. They acted according to this. If property fell while she was a Shomeres Yavam, even if he gave a Ma'amar, she may sell the Peros l'Chatchilah.

Rashba (cited in Ran 39a DH Nechasim): The Yavam does not receive Peros, for even the husband receives Peros only in exchange for the obligation to redeem her, and the Yavam is exempt from this. It seems that even after Yibum he does not eat Peros of her Nichsei Melug. Her Kesuvah is not collected from the Yavam's property (rather, from that of the Mes), so she had no Tnai Kesuvah. The Gemara (Kesuvos 53b) did not resolve whether or not her daughter is fed. She is not redeemed from the Mes' property, for we do not apply 'I will return you to be my wife'. She is not redeemed from the Yavam's property, for she has no Kesuvah from him. Therefore, the Peros are hers. However, when there was no property from the Mes we enacted a Kesuvah from the Yavam. Then she also has Tnai Kesuvah including redemption, and he eats the Peros. However, the Gemara in Yevamos connotes that he (always) gets Peros. It asked why the Mishnah discusses who gets the property itself after her death, instead of who eats the Peros during her lifetime! This requires investigation.

Ran (ibid.): The Gemara in Yevamos proves that the Yavam has the same rights to Peros as he has in the land itself. We must say that when property fell to her during her marriage, the Yavam eats half the Peros. This is not in his own merit. Rather, he inherits his brother. Even though the Yavam need not redeem her, Chachamim did not say that whoever need not redeem does not eat Peros. Rather, they obligated him to redeem her whenever she can resume to be his wife. However, when he dies, his heirs inherit the Peros even though they need not redeem her. The Rashba learned from the question of a Yevamah's daughter that even after Yibum he does not eat Peros. The Gemara in Yevamos proves that he eats only what the Mes acquired. Nevertheless, it seems that after Yibum he redeems her and eats Peros even of property that fell to her before Yibum. Since he merits Peros due to Nisu'in, he must redeem her. It is unlike feeding her daughter. That is not in exchange for anything else. It is a mere Tnai Kesuvah. It is unreasonable to have Tnai Kesuvah without a Kesuvah!

Rambam (Hilchos Ishus 22:10): If property fell to a Shomeres Yavam, she may sell it or give it away. He does not receive Peros even from Tzon Barzel that she entered to his brother, until he does Yibum. If she died while she was Shomeres Yavam, her paternal heirs inherit the Melug property and half the Tzon Barzel. Her husband's heirs inherit the Kesuvah and half the Tzon Barzel.

Rebuttal (Ra'avad): We discuss Nichsei Melug like Tzon Barzel, i.e. it fell while she was married to his brother. The husband's Yad is stronger than hers, and the Yavam's hand is equal to hers, so the Yavam shares the Peros.

Magid Mishneh: He has no Peros of Nichsei Melug because he need not redeem her. It is not clear why the Rambam says that he does not share Peros of Nichsei Tzon Barzel, just like he inherits half of them if she dies.

Beis Yosef (EH 160 DH v'Zeh, citing Rivash 104): No one defends the Rambam regarding Peros of Tzon Barzel. Redemption was enacted in exchange for all Peros of her property. A Yavam does not eat Peros of Nichsei Melug that fell while she was Shomeres Yavam, therefore he need not redeem her.

Rosh (4:13): BaHaG rules like Abaye, who says that his Yad is like hers, because Rav Papa, who is Basra, supports him. It is not included in YALKGM (the six places where the Halachah follows Abaye against Rava), because the argument involves others. Others rule like Rava, because he explains the Reisha and Seifa similarly. It seems that the Rif holds like this. He omitted the opinions in Yevamos and brought them in Kesuvos; we understand that the Halachah follows Rava.

Poskim

Shulchan Aruch (EH 160:6): A Yavam does not receive Peros from Nichsei Melug of a Shomeres Yavam. He receives half the Peros of the Nichsei Tzon Barzel that she entered to his brother.

Beis Shmuel (9): The same applies to Tzon Barzel that she entered to the Yavam.

Shulchan Aruch (ibid.): Some say that even in Tzon Barzel he has no Peros until he does Yibum.

Rebuttal (Taz 3): Why did the Shulchan Aruch bring the Rambam's opinion? Regarding Tzon Barzel he is refuted; there is no defense.

Rema: The first opinion is primary. Some say that Nichsei Melug that fell when while she was married are like Tzon Barzel, and they share them. Similarly, they divide her inheritance if she dies. When the Peros are hers, she can sell the land itself according to her share of the Peros.