Halakhah sa Exodo 21:8: Sefer HaChinukh, Mishneh Torah, Positive Mitzvot & Mishneh Torah, Negative Mitzvot

The commandment of designation of a Hebrew bondwoman: To designate a Hebrew bondwoman, meaning to say that the Israelite that acquired a Hebrew bondwoman marry her as a wife or give her to his son as a wife, as it is stated (Exodus 21:8), “If she is bad in the eyes of her master, who designated her for himself, he must let her be redeemed.” And they, may their memory be blessed, said (Rashi on Exodus 21:8) that here is a hint for you that there is a commandment of designation. And they, may their memory be blessed, explicitly said (Bekhorot 19a) that the commandment of designation takes precedence to the commandment of redemption.

The commandment of redemption of a Hebrew bondwoman: To redeem a Hebrew bondwoman, as it is stated (Exodus 21:8), “he must let her be redeemed.” And that is a positive commandment, meaning to say that the master that acquired her, help her in her redemption and give her room to go back to the house of her father. [It is] like they, may their memory be blessed, said (Kiddushin 14b), “He reduces the price and she leaves.” [This] means to say that if he took her for [the price of] sixty dinars over six years and she worked three years and gathered thirty dinars, he should take them and send her away. And he should not claim about her that she must finish the years of her bondage regardless, or say, “My money was sitting idly with you; if you want to leave, add the profit to me [that the money should have produced while it was idle]” — as this is only evil-heartedness. And for the Children of Israel who are the children of kings, merciful ones [who are] the children of merciful ones, it is fitting to do kindness with the creatures, even those who serve them, and even [if it is] for one day.

That the one who acquires the Hebrew bondwoman from the father not sell her: That anyone who acquires a Hebrew bondwoman not sell her to another man ever, as it is stated (Exodus 21:8), “he shall not have the right to sell her to a foreign people, etc.” And the explanation [of the phrase] is like [Onkelos’ Aramaic] translation, “to another man.” And it was stated with this wording to distance this thing — meaning to say that if he sells her to a second man, it is for this poor little one similar to if he sold her to a foreign people.