Gemara

3b - Question: A Mishnah teaches that a man may be Mekadesh his daughter (before Bagrus) through money, a document, or Bi'ah. What is the source that money works, and that the father gets the money?

Answer (Rav Yehudah): "V'Yotzah Chinam Ein Kasef" (an Amah (Yisraelis slave) goes free at Na'arus (bringing two hairs after 12 years). Her master gets no money, but her father gets money (when she leaves him through Kidushin).

4a - Question: A Beraisa uses "v'Yotzah Chinam Ein Kasef" for another law (to teach that an Amah goes free at Bogeres, and even at Na'arus)!

Answer (Ravina): The verse says Ein Kesef (not An Kesef) to teach both of these.

41a (Rav Yehudah): One may not be Mekadesh a woman without seeing her. Perhaps he will see in her something displeasing, and despise her, and transgress "you will love your fellow man like yourself"!

A woman may become Mekudeshes through a Shali'ach, for she will love her husband (even if she did not see him beforehand);

(Reish Lakish): A woman prefers to be married than to live alone.

(Mishnah): A man can be Mekadesh his daughter when she is a Na'arah.

Inference: One may be Mekadesh a Na'arah, but not a minor. This supports Rav:

(Rav): One may not be Mekadesh his daughter when she is young, until she matures and says whom she wants to marry.

64b (Mishnah): If one was Mekadesh his daughter and is unsure which, surely, he didn't Mekadesh his Bogeres (even if he was a Shali'ach to be Mekadesh her).

Surely, he did a Mitzvah incumbent on him (to be Mekadesh his minor), and not something not incumbent on him (being Mekadesh his Bogeres).

81b: Rav Chisda told R. Acha bar Aba (his father-in-law) that Rav Chisda's daughter is Mekudeshes.

R. Acha: You transgressed Rav, who says that a man should not Mekadesh his daughter until she matures, and knows whom she wants to marry!

Yevamos 62b (Beraisa): "V'Yodata Ki Shalom Ohalecha... " applies to one who ... and marries off his sons and daughters Samuch l'Pirkan (close to adulthood).

Kesuvos 57b (R. Aba bar Levi): We do not arrange to make Nisu'in for a minor, but we may arrange Nisu'in for her now for when she grows up.

Nidah 66a: Rav Chaviva was Mekadesh his daughter to Ravina's son. Ravina postponed the Chupah for a week, for Rava's law (that a woman must count seven clean days after consenting to Nisu'in) applies even to a minor.

Rishonim

The Rif and Rosh (16b and 2:1) bring the Gemara on 41a.

Ran (DH keshe'Hi): Even though a woman prefers to be married than to live alone, that refers to an adult who made a Shali'ach. She willingly accepted (whomever the Shali'ach will find). We are not concerned lest she change he mind. A minor becomes Mekudeshes without her consent. Perhaps when she matures, she will not desire him.

The Rif and Rosh (Yevamos 19b and 6:1) bring the Gemara in Yevamos.

Rambam (Hilchos Ishus 3:19): One can be Mekadesh his daughter to anyone he wants when she is a minor or Na'arah, but Chachamim commanded not to be Mekadesh a minor, until she matures and says 'I desire Ploni.' Similarly, a man should not be Mekadesh a minor.

Rambam (Hilchos Isurei Bi'ah 21:25): Chachamim commanded that one marry off his sons and daughters Samuch l'Pirkan. If he will leave them (single), they will come to Zenus or thoughts (of sin).

Mordechai (Kesuvos 179, cited in Hagahos Ashri Kesuvos 5:10): Rashi allows arranging a marriage for his minor daughter, but not Kidushin, due to Rav's law. R. Tam says that perhaps the Halachah does not follow Rav. Rav Chisda was not concerned for Rav's law. R. Baruch proves this from Nidah 66a.

She'alas Ya'avetz (1:14): The episode with Rav Chisda connotes that the Halachah follows Rav, for Rav Chisda double payment answer Rav Acha's rebuke! Perhaps we rely on Rav Chisda, for he did an act. The Stam Mishnah supports Rav. It seems that Tosfos rules like Rav, and tried to justify our custom. The proof from Rav Chaviva is not solid. Perhaps she was in her 12th year, and did not yet bring two hairs. She is a minor regarding blood, but an adult for consent to Kidushin, for we check her vows. Yevamos 62b supports this. Kidushin 64b connotes that it is a Mitzvah to marry off minors of any age. I.e. later it will be a Mitzvah incumbent on him, unlike a Bogeres.

Note: If a man has a minor in her 12th year, we should say that surely he was Mekadesh her, and not a minor before 12 years (for now it is forbidden)!

Ya'avetz (ibid.): One may arrange Nisu'in for a girl in her 12th year. The reason we delay Nisu'in until adulthood is lest she become pregnant and die (Yevamos 12b). Rav Chaviva's daughter was almost 12, so she would not deliver before adulthood. Alternatively, great people may rely on a miracle.

Mordechai (ibid.): R. Eliyahu says that we (Yisrael) are few in number, so we are Mekadesh minors, lest the other party make Kidushin with someone else.

Tosfos (Kidushin 41a DH Asur): Our custom is to be Mekadesh our daughters while minors. In exile we are not always able to give a dowry. If he is not Mekadesh her now, perhaps later he will not be able to, and she will never marry!

Poskim

Shulchan Aruch (EH 37:8): It is a Mitzvah not to be Mekadesh one's daughter when she is a minor, until she matures and says 'I desire Ploni.'

(Bach DH u'Mah she'Chosav): The Rif, Rosh and Tur bring this, and also (Siman 1) the Beraisa that praises one who marries off his children Samuch l'Pirkan, i.e. at the beginning of year 13 for a boy, or 12 for a girl! They must hold that Rav forbids to be Mekadesh one's minor before she says that she desires Ploni. One she says so, it is a Mitzvah to be Mekadesh her close to maturity, even though she is still a minor. Rav said 'until she matures', for usually she does not desire a particular man before this. Our texts do not say 'until she is Tagdil (adulthood)', rather, 'Tigdal' (develops intellect). Rav Acha rebuked Rav Chisda for marrying off his minor daughter. She was mature enough to know whom she wants (Rav Acha did not know this). The Gemara (64b) calls being Mekadesh one's minor 'a Mitzvah incumbent on him.'

Drishah (9) and Beis Yosef (Siman 1 DH u'Mah she'Chosav Aval): The Rambam and Tur explain that Samuch l'Pirkan means shortly afterwards. Tosfos says that it means (a year or half-year) before. This is not difficult, for shortly before she has intellect to know whom she desires.

Rebuttal (Bach DH umi'Kol): All Poskim say that Samuch is shortly before.

Chelkas Mechokek (14): Perhaps one may tell her 'Tze'i v'Kabli (go receive) Kidushin yourself.' In any case it is a Mitzvah to wait until she matures.

Rebuttal (Beis Shmuel 11): No one mentioned Tze'i v'Kabli! Rather, the Halachah does not follow Rav, but it is a Mitzvah to fulfill his teaching.

Rema: Some say that nowadays our custom is to be Mekadesh our daughters while minors, for in exile we are not always able to give a dowry. Also, we are few in number, and we do not always find a proper match.

Bach (ibid.): We can say that all cases of a minor who became Mekudeshes were after she was mature enough to say whom she desires.