Exodus 21:5-9

But if the slave plainly says, ‘I love my master, my wife, and my children; I will not leave as a free man,’

then his master shall bring him to God, then he shall bring him to the door or the doorpost. And his master shall pierce his ear with an awl; and he shall serve him permanently.

“Now if a man sells his daughter as a female slave, she is not to go free as the male slaves do.

If she is displeasing in the eyes of her master who designated her for himself, then he shall let her be redeemed. He does not have authority to sell her to a foreign people, because of his unfairness to her.

And if he designates her for his son, he shall deal with her according to the custom of daughters.