Exodus 21:2-6

“If you buy a Hebrew slave, he shall serve for six years; but on the seventh he shall leave as a free man without a payment to you.

If he comes alone, he shall leave alone; if he is the husband of a wife, then his wife shall leave with him.

If his master gives him a wife, and she bears him sons or daughters, the wife and her children shall belong to her master, and he shall leave alone.

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.