The 264th prohibition is that we are forbidden from enslaving a yefas to'ar after having had intercourse with her. By "enslaving," I mean to make her a servant and leave her together with the rest of your servants who serve you.

The source of this prohibition is G‑d's statement1 (exalted be He), "Do not keep her as a servant, since you have had relations with her."

The Sifri2 says, "The phrase lo sisameir ba means that you shall not use her as a servant." It has been demonstrated to you that these two prohibitions prohibit two distinct acts: not to sell her to someone else, and also not to leave her under you as a servant. Rather, you should follow G‑d's command (exalted be He), "You must send her away free." The same is explained regarding one who kidnaps someone, "and forces him to serve3 and then sells him."4 Our Sages said,5 "[He is guilty] as soon as he brings him into his property and forces him to serve."

The details of the law of the yefas to'ar are explained in the first chapter of tractate Kiddushin.6