For instance, a man can sell his daughter as a concubine according to Exodus 21:7-11
Deuteronomy prescribes the death penalty for anyone who kidnaps Israelite men to enslave them (Deuteronomy 24:7.When a man sells his daughter as a concubine, she is not to leave as the male slaves do. If she is displeasing to her master, who chose her for himself, then he must let her be redeemed. He has no right to sell her to foreigners because he has acted treacherously toward her. Or if he chooses her for his son, he must deal with her according to the customary treatment of daughters. If he takes an additional wife, he must not reduce the food, clothing, or marital rights of the first wife. And if he does not do these three things for her, she may leave free of charge, without any payment.
It requires that the people of cities who surrender during war be enslaved (Deuteronomy 20:1-15).If a man is discovered kidnapping one of his Israelite brothers, whether he treats him as a slave or sells him, the kidnapper must die. You must purge the evil from you.
Leviticus explicitly allows participation in the slave trade, including female slaves who would become concubines (Leviticus 25:44-46).
Your male and female slaves are to be from the nations around you; you may purchase male and female slaves. You may also purchase them from the aliens residing with you, or from their families living among you—those born in your land. These may become your property. You may leave them to your sons after you to inherit as property; you can make them slaves for life. But concerning your brothers, the Israelites, you must not rule over one another harshly.