Gemara

(Rava): The Halachah is, if one sells a field to his wife, she does not acquire. He eats the Peros.

Question: Saying that he eats the Peros (in the case of a sale) implies that she acquires, but Rava said that she does not acquire!

Answer: If he had not seen her money (he only pretended to sell in order to get her to show the money she took from him) she does not acquire. If he had seen her money, she acquires, but he eats the Peros.

(Beraisa): We do not accept deposits from a (married) woman, slave or child. If Reuven took a deposit from a woman or slave, he returns it to him or her. If the woman or slave died, he returns it to the Ba'al (husband or owner);

If he took a deposit from a child, he sells it and buys a Segulah. If the child dies, he gives the Segulah to the child's heirs.

(Rav Chisda): A Segulah is a Sefer Torah (for one may sell it only to get married).

(Rabah bar Rav Huna): It is a date tree from which he eats dates.

Rishonim

Rif: We do not accept deposits from a woman, slave or child. If Reuven took a deposit from a woman or slave, he returns it to him or her. If the woman or slave died, he returns it to the Ba'al. If he took a deposit from a child, he sells it and buys a Segulah. If the child dies, he gives it to the child's father.

Nimukei Yosef (DH Ein): We are concerned lest they stole,. Accepting a deposit aids the thief. She is believed to say that money she has was given to her for a gift. The Yerushalmi says that they enacted that he receives her Metzi'os, lest she steal from him and say that she found a Metzi'ah. It asked, perhaps she will steal and claim that she received a gift! The Ri and Ritva say that she is believed to say that the gift was on condition that her husband has no rights in it, even for Peros. Our Gemara supports this, for we return it to her (without informing her husband - Hagahos me'Eretz Yisrael, based on Tosfos). If Reuven returned to the minor and it was lost, he is exempt. He should make a Segulah for Hashavas Aveidah, to be Yotzei Yedei Shamayim. One may give to the minor's overseer. The Rashba says that if the child reached the age of Pa'utos (six to 10, depending on his sharpness), we return to him, for he may buy and sell Metaltelim.

Rambam (Hilchos Ishus 22:32): We do not accept deposits from a woman, slave or child. If Reuven took a deposit from a woman or slave, he returns it to him or her. If the woman or slave died, he returns it to the Ba'al. If he took a deposit from a child, he sells it and buys a Sefer Torah, or something from which he will eat the Peros.

Hagahos Maimoniyos (70): Ra'avan says that if the Ba'al (or father) demanded it, we return to him, for a Ba'al acquires what his wife or slave acquires and what his child finds. If Reuven returned it to the Ba'al, the Ba'al need not return it, and she has no claim against Reuven. If she sold something and the Ba'al says that she stole it, the buyer keeps it for Takanas ha'Shuk (lest people fear to buy). The RI says that the Ba'al may not take it from Reuven, but if he did, he keeps it, for the Gemara did not teach the Chidush that he must return it.

Magid Mishneh (Hilchos She'elah 7:10): The Rashba says that the Rambam means that he may even return to the depositor. He does not forbid to return to the Ba'al.

Rivash (50): Even if she does business in the house, Reuven returns to where he received from, i.e. her. The Rambam and Ramban say that she is not believed without a proof to say that money she holds is hers. Even so, they say that one returns to her. Her husband can claim against her that he has rights to Peros.

Question (Chelkas Mechokek EH 86:6): What is his proof from the Rambam and Ramban? They do not discuss a woman who does business in the house! Surely, if the husband does not protest, we need not be an overseer for him, but the Rivash connotes that even if he protests, we return to her! This is astounding.

Defense (Gra 6): The Rivash learns from the Gemara, which says that if the slave died, we return to his master.

Chazon Ish (EH 72:20): The Gra holds that the slave is not believed when his master claims (that he stole), for if not, we would not return to the master even after the slave died. However, Tosfos believes the slave against his master's claim, yet says that we return to the master after the slave died! Perhaps the Gra's proof is like the Rambam and Ramban.

Chazon Ish: Tosfos holds that we return to the slave even if the master protests. If the slave died, the master is believed, for no one else claims it. As long as the slave is alive, even if he was freed, and he is Muchzak in the money, he has authority over it, even if it was another's. Reuven holds it for the slave. The Rashbam connotes that after he dies, the master gets it, even if the slave fathered a child after he was freed. Why doesn't his heir inherit his right to the money? If the money was given for freedom, the heirs do not get it for it was not their father's, even though he was like a borrower of Shomer on the money. The Ra'avan holds that it returns to the slave's heirs.

Beis Yosef (EH 86 DH Kasuv bi'Teshuvas): The Rashba (906) says that if one bought from her husband with hidden money, she does not acquire, for he merely induced her to reveal the money. However, he only eats the Peros. He may not seize the money entirely for himself.

Rosh (ibid): If she died, we return to him, for even if a gift was given on condition that he has no rights to it, he inherits it. We return a slave's deposit to the slave. We suppose that it was deposited with him, or it was given (to redeem him, i.e.) on condition that he go free through it. If he dies, it goes to his master, for presumably he took it from there, but while alive he was believed to say that it was a deposit or for freedom. Therefore, even if he died after he was freed, it goes to his master. If a divorced woman died, it goes to her heirs.

Poskim

Shulchan Aruch (EH 86:1): We do not accept deposits from a married woman. If Reuven took a deposit from her, he returns it to her.

Beis Yosef (DH u'Piresh Rashbam): The Rashbam says that we do not return it to her husband, for we do not establish her to be a thief. After the slave dies, we return it to his master, for presumably he acquired whatever his slave acquired.

Chelkas Mechokek and Beis Shmuel (1): Perhaps she stole, and if we do not take from her, perhaps she wil return it to her husband.

Beis Yosef (DH Kosav ha'Rivash): The Rivash (50) says that this is even if she does business in the house.

Rema: If she went overseas, and her husband came and demanded it from Reuven and said that his wife stole it from him, I think that he does not give it to him until she comes or dies.

Beis Shmuel (4): This is unlike the Rambam, who says that one may return it to her husband. Or, perhaps the Rambam does not say so when he claims that she stole it and wants to keep it for himself.

Rema: If she did not say anything, and died (he gives to her heirs).

Shulchan Aruch (ibid): Some say that if she does business in the house, she is not believed to say that the money is Ploni's.

Rema: However, as long as she is alive, we return to her.

Chelkas Mechokek (6): This is astounding! Since her husband can say that it is his, why do we return to her without a proof? He should have written that if the husband does not protest, we return to her.

Rema: However, if he returned to her husband, he is exempt, even if she does not do business in the house.

Chelkas Mechokek (7): The Mordechai (Bava Basra 546) was unsure about this. He leaned to exempt Reuven, but the money is Nichsei Melug, just like if she bought from him with hidden money. If the money was not hidden, all agree with the Rambam (that it is Nichsei Melug).

Beis Shmuel (8): The Poskim other than the Rambam hold that he can totally take hidden money. However, this is like a Shali'ach who paid a debt and did not take back the document. The borrower claims from the Shali'ach, and the Shali'ach claims from the lender. Here also, she claims from Reuven, and Reuven claims from her husband. However, perhaps here she has no claim against Reuven, unless the money was exposed, for then she can say that it was totally hers.