Gemara

(Beraisa): If a father wrote that he will give to his daughter fruit, clothing and Kelim and she died, the husband does not receive them;

R. Noson says that he does.

Suggestion: These Tana'im argue like R. Elazar ben Azaryah and Chachamim:

(Mishnah): If she was widowed or divorced, whether from Eirusin or Nisu'in, she collects the entire Kesuvah;

R. Elazar ben Azaryah says, if it was from Nisu'in she collects the full Kesuvah. If it was from Eirusin she collects only the basic Kesuvah (100 or 200).

Any Tosefes (addition) was written only on condition that he make Nisu'in.

Chachamim of the Beraisa say that he does not receive the dowry, like R. Elazar ben Azaryah. R. Noson says that he receives it, like Chachamim of the Mishnah.

Rejection: No, even R. Noson holds like R. Elazar ben Azaryah. R. Elazar said only that the husband pays Tosefes only if he did Nisu'in, but he could agree that her father gives even after death;

The father gives due to Chitun (uniting of the families), and this happened.

48b (Beraisa): If she entered the husband's courtyard with him for Nisu'in, if she dies, her husband inherits her. This is even if her father has the Kesuvah.

66a (Mishnah): If a father pledged to give a dowry and the husband died before Nisu'in, the father can tell the Yavam 'I wanted to give to your brother, but I do not want to give to you.'

(Beraisa): We need not teach that one who pledged a dowry to a Chacham can say this to an ignoramus Yavam. Rather, even if he pledged to an ignoramus and the Yavam is a Chacham, he can say 'I do not want to give to you.'

102b (Rav): If Yakov agreed to marry his son to Moshe's daughter, each father agreed to give a certain amount to his child, and the children became Mekudeshos right then, the verbal promises are binding.

(Rava): Through the happiness that they are marrying their children to each other, they decide absolutely to give like they promised, and this is binding.

Rishonim

The Rif (17b and 29a) brings these Gemaros.

Rosh (4:9): Rashi explains that the father pledged during Eirusin. R. Tam disagrees, for the Mishnah says that there was Nisu'in! Also, why does R. Noson say that her husband acquired? The stipulation was 'the property will go with her from her father's house to her husband's house!' Also, we conclude that the father gives due to Chitun, and this happened. Kidushin is not Chitun! The Gemara on 102b discusses Kidushin and says that the promises are binding due to the Simchah of Chitun. There, it means that in the end there will be Chitun. R. Tam explains that here (47b) we discuss after Nisu'in. The father promised to give, and she died before he gave. The first Tana holds that surely the father promised only on condition that his daughter will benefit from the property. R. Noson disagrees; therefore, the husband acquired. The Gemara said that these Tana'im argue like R. Elazar ben Azaryah and Chachamim. Even though these Tana'im discuss after Nisu'in, and R. Elazar ben Azaryah and Chachamim discuss during Eirusin, the Gemara equated them. R. Tam and R. Chananel rule like Chachamim, that the husband does not acquire. Even though 'R. Noson was a judge, and descended to the depth of the law', we usually follow him in monetary laws), but not against a majority. Also, the Halachah follows R. Elazar, and Chachamim hold like him. We said that even R. Noson could hold like him, but this is a flimsy rejection and we do not rely on it. When the husband died, the father need not give to the Yavam.

Rif (29a): The Yerushalmi says that these are matters that are acquired verbally. (Some texts - the Yerushalmi asks why the father can retract, for these matters are acquired verbally!) A Beraisa teaches that one who pledges does so on condition that there will be Nisu'in. Therefore, the father need not give to the Yavam. Some explain differently, but I hold like I wrote.

Rosh (ibid.): The Yerushalmi answers by establishing the case to be that he pledged on condition that there will be Nisu'in. (This is the other explanation to which the Rif alludes.) Without a stipulation, the father would need to give to the Yavam. This is because his daughter will benefit from it. A Beraisa teaches that if she entered the husband's courtyard with him for Nisu'in, if she dies, her husband inherits her, even if her father has the Kesuvah. This is like R. Noson.

Support (for Rif - Rosh 6:3): The Beraisa says that the father pledges on condition that there will be Nisu'in, i.e. every father has this intent. It does not say 'this is when he pledged on condition...' Rav Hai Gaon says that this is when he pledges to his son-in-law, but if he pledged to his daughter at the time of Kidushin 'I will give this amount to my daughter', she acquires it, even if her husband dies. He cannot say that he gave on condition that there will be Nisu'in, for he pledged to his daughter and she acquired. The one who wrote this in Rav Hai's name did not explain well. It sounds as if the father must give even if the husband died and the Yavam did not do Yibum. This is unreasonable. Surely, he pledged only on condition that there will be Nisu'in! If she died and left a son, surely her son does not inherit the gift! However, if she did Yibum, her father cannot say 'I wanted to give to your brother (but not to you)', for he pledged to his daughter, and the Kidushin did not lapse. A Gaon ruled that if a father pledged to his son-in-law at the time of Kidushin and gave it before Nisu'in and his daughter died leaving a son, the husband returns the money to the father. Any pledges is on condition that there will be Nisu'in. If he gave money to his daughter for Nisu'in Stam, without specifying with which man, she acquired. If she became Mekudeshes, even if the Arus died and the Kidushin was Batel, the father cannot retract.

Ran (29a DH Gemara): This is when the father said 'when you have Nisu'in with my daughter, I will give to you this amount. Had the Choson done Nisu'in, he would have acquired through the words at the time of Kidushin. However, since he died, the father can tell the Yavam 'I wanted to give to your brother, but not to you.' However, he pledged at the time of Kidushin 'I will give this amount to my daughter', she acquires, even if her husband dies. Her father cannot say that he gave on condition that there will be Nisu'in with him, for he pledged to her and she acquired.

Rambam (Hilchos Ishus 23:15): If a father pledged for his daughter, she does not acquire the gift until Nisu'in. Also a son does not acquire (what his father pledged to him) until Nisu'in. Anyone who pledges does so only on condition that there will be Nisu'in. Therefore, if one pledged to his son-in-law and the son-in-law died before Nisu'in, the father can tell the Yavam 'I wanted to give to your brother, but I do not want to give to you.' He can say so even if he pledged to an ignoramus and the Yavam is a Chacham, and she desires him.

Tosfos (47 DH Kosav): R. Tam enacted that the father can retract his gift if the Choson died within a year (of Nisu'in). He retracted from this at the end of his life. According to R. Tam, why does the Gemara distinguish between what he promises to her and what her father pledges to him? It should distinguish between before and after Nisu'in! Many Amora'im say that the Choson inherits the dowry if she died after Mesirah to his Sheluchim. R. Tam must say that this is when the dowry is in the Choson's Reshus.

Poskim

Shulchan Aruch (EH 53:2): If a father pledged for his daughter, she does not acquire the gift until Nisu'in.

Beis Shmuel (5): He pledged to his son-in-law for his daughter. In Sa'if 3 he pledged to his daughter. Even though it says 'some say that', we need not say that they argue.

Shulchan Aruch (ibid.): Similarly, a son does not acquire until Nisu'in. Anyone who pledges does so only on condition that there will be Nisu'in. Therefore, if one pledged to his son-in-law (Rema - or son) and he died before Nisu'in, the father can tell the Yavam 'I wanted to give to your brother, but not to you.' He can say so even if he pledged to an ignoramus and the Yavam is a Chacham, and she desires him.

Chelkas Mechokek (7): Also when he pledged to his son and his son died before Nisu'in, he can tell the Yavam 'I wanted to give to your brother, but not to you', even if the Yavam is a Chacham.

Beis Shmuel (6): The Maharik (73) says that the father can retract if his son died within a year of Nisu'in. I do not understand why the Darchei Moshe says that he died before Nisu'in. (Note: Darchei Moshe ha'Aruch (2) cites the Mordechai (190), who says that if the Mes wrote a Kesuvah, the Yavam acquired and the father cannot say 'I do not want to give to you.')

Shulchan Aruch (3): Some say that if one pledged to his daughter, e.g. at the time of Kidushin he said 'I will give this amount to my daughter', she acquires it in one aspect. I.e. if she does Yibum, her father cannot say 'I wanted to give to your brother (but not to you)', for the pledge was to his daughter, and the Kidushin did not lapse. The Yibum was due to the Kidushin.

Chelkas Mechokek (8): If she did not fall to Yibum, and says 'I will marry someone else. What does it matter whom I marry?', this helps only if he gave her the money before Eirusin and said Stam 'it is for a dowry.'

Beis Shmuel (7): This is like the Rosh. It seems that the Ran disagrees (she keeps the money even if it was given after Eirusin).