These are the ordinances that you shall set before them:
When you buy a male Hebrew slave, he shall serve six years, but in the seventh he shall go out a free person, without debt.
If he comes in single, he shall go out single; if he comes in married, then his wife shall go out with him.
If his master gives him a wife and she bears him sons or daughters, the wife and her children shall be her master's and he shall go out alone.
But if the slave declares, "I love my master, my wife, and my children; I will not go out a free person,"
then his master shall bring him before God. He shall be brought to the door or the doorpost; and his master shall pierce his ear with an awl; and he shall serve him for life.
References for Exodus 21:6