Until what age may a man sell his daughter?
Rashi (citing Erchin, 29b): It is only when she is a Ketanah (under twelve), because in Pasuk 11, the Torah teaches us that, the moment she brings Simanim of Na'arus, she goes free - Kal va'Chomer may her fatherno longer sell her. 1
Moshav Zekenim: We find that one can sell a field in Yovel, and it returns immediately (Erchin 29b). Perhaps he can sell her, and she is freed immediately!
Why does the Torah write "ve'Chi Yimkor Ish es Bito" and not 've'chi Yimkor Av es Bito'?
Oznayim la'Torah: Because it is unusual for a father to sell his daughter, and he only does so due to poverty. 1
Oznayim la'Torah (citing Kidushin, 20a): And only after he has sold his Metalt'lin, his house and his fields
What are the implications of "ve'Chi Yimkor Ish es Bito ... "?
Sotah, 23b: It implies that a man may sell his daughter, but not a woman.
Mechilta: It implies a. that a man may sell his daughter but not his son, and b. that a woman may not sell herself.
Why does the Torah add the word "le'Amah"?
Kesuvos, 47a: To teach us that, just as the work of an Amah Ivriyah's hands belongs to her master, so too, does the work of a daughter's hands belong to her father.
Kidushin, 39b: To teach us that he is permitted to sell her as an Amah exclusively
What does the Torah mean when it writes "Lo Seitzei ke'Tzeis Avadim"? Which Avadim is it referring to?
Ramban #2 (citing Ba'al Halachos Gedolos): This Pasuk is actually a prohibition against sending away an Amah Ivriyah 3 after knocking out her eye or her tooth, and if he does so, he transgresses a La'av.
Seforno, Ramban #3 and Rashbam: She should not go out after six years (or in the Yovel) like an Eved Ivri - It is not correct to purchase a Jewish girl as a maidservant, unless one intends to marry her. 4
Moshav Zekenim: I.e. a permanent tooth of a girl of 10 or 11. Even an Eved Cana'ani is not freed for baby teeth!
It cannot mean that an Amah Ivriyah does not go out after six years or in the Yovel - like Avadim Ivrim, since the Torah equates the two in Devarim (15:12). And it is due to the same Hekesh that an Eved Ivri does not go out with 'a tooth and an eye' either. Moreover, the Torah never calls Avadim Ivrim 'Avadim' (S'tam).
As it is a K'nas in the case of an Eved Cana'ani (Ibid). See Ramban, who explains why we would otherwise have thought that an Amah Ivriyah goes free with Shen ve'Ayin, and why it is a prohibition, according to the B'hag (Refer to 21:7:3:1).
Why does the Torah draw a distinction between an Amah Ivriyah (and an Eved Ivri on the one hand and an Eved Cana'ani on the other, with regard to going free with Shen ve'Ayin?
Ramban: Because sending her away after giving vent to his anger with her would be an evil thing to do a. bearing in mind that ultimately, there is hope that he performs Yi'uyd with her, and b. because ir often happens that the value of her tooth or her eye are worth more than that of her work, and he tries to get out of paying for the damage by sending her away. 1
Oznayim la'Torah: Because whereas one is permitted to strike an Eved Cana'ani, in order to encourage him to do anything that one expects of him, and setting him free is a K'nas for having going too far, it is forbidden to strike an Eved Ivri or an Amah Ivriyah
This only answers the question on the Amah Ivriyah however, not the question on the Eved Ivri.
Why does it say "she does not go out k'Tzeis ha'Avadim", and not just 'ka'Avadim'!
Moshav Zekenim #1: We extrapolate that she does not go out like Avadim, but she can be acquired like Avadim - with a Sh'tar (a document).
Moshav Zekenim #2, Da'as Zekenim: One may not tell an Amah Ivriyah to go buy things in the market (Hadar Zekenim - to go to draw water or grind) like one tells an Eved, for the honor of a Bas Melech (Yisraelis) is to be inside. Rather, she works in the house.
QUESTIONS ON RASHI
Rashi writes that a father cannot sell a Na'arah, from a Kal v'Chomer. We should know this already, for a Drashah ("Bito
Moshav Zekenim: If not for the Kal v'Chomer, I would have used the Drashah to teach about a Na'arah after Nisu'in 1 (and she was widowed or divorced; her father cannot sell her. Due to the Kal v'Chomer, the Drashah teaches about a Na'arah before a Nisu'in, and a [widowed or divorced] Na'arah after Nisu'in keeps her earnings.
Moshav Zekenim citing R. Shmuel of Plaiza: Without the Kal v'Chomer, we would establish the Drashah to discuss a Bogeres, and "Ki Yimkor" to discuss a Na'arah.
Da'as Zekenim, Hadar Zekenim: We can learn from the Drashah, or from the Kal v'Chomer. The Kal v'Chomer is simpler.
Riva citing R"A: Without the Kal v'Chomer, we would establish the Drashah to discuss a Na'arah that he cannot sell, e.g. he previously sold her to be an Amah Ivriyah.
Riva #1: Without the Kal v'Chomer, we would establish "Ki Yimkor" to discuss a Na'arah. However, since he cannot sell a minor to keep working into Na'arus, we could not infer that he owns a Na'arah's earnings. 2
Riva #2: We need the Drashah to teach that a Bogeres keeps her earnings. 3
Moshav Zekenim: Why do we use the Drashah to teach about a Na'arah? Perhaps it teaches about a minor after Nisu'in! We can say that all the more so, he owns earnings of a Na'arah who never had Nisu'in,
Since he can sell a Na'arah, does this not shows that he owns her earnings, and Simanei Na'arus free a minor due to a Gezeiras ha'Kasuv (perhaps it is because her body changed), and not because she now owns her earnings? Perhaps we would say that a Na'arah is sold primarily for marriage (the sale is always for less than six months), and Agav the buyer receives her earnings, even though they did not belong to the father. (PF)
If he owns a Bogeres' earnings, we can say that he cannot sell her, for he has no Reshus to marry her off. However, how can she marry herself off and uproot her earnings from him? Perhaps the marriage is primary, and Agav her husband receives her earnings, even though they belonged to the father. (PF)
Rashi writes that a Hekesh teaches that just like an Amah Ivriyah does not go out due to a limb [that her master knocked out], also an Ivri. We should know this already from a Kal v'Chomer from Ivriyah, who goes out with Simanei Gadlus!
Moshav Zekenim, Riva #1: We can challenge the Kal v'Chomer - a woman is not sold for her theft, but a man is (so perhaps it is easier to free him). 1
Moshav Zekenim citing Ri, Riva #2: There is no source to say that an Ivri goes out due to a limb. If you make a Kal v'Chomer from an Eved Cana'ani, an Ivriyah refutes it! The Hekesh is needed for other matters; it is brought as a support for this law, but in truth, it is not needed for this.
Riva, Moshav Zekenim (11): This is difficult. (Since a woman is not sold for her theft, it should be easier to free her!) Rather, there is no Kal v'Chomer, because freedom due to Simanei Gadlus does not apply to a man, for only an adult can be an Eved Ivri!