Exodus 21:2-6

2“Whenever you buy a Hebrew slave, he will be your slave for six years. In the seventh year he may leave as a free man, without paying for his freedom.

3If he comes to you by himself, he must leave by himself. If he comes as a married man, his wife may leave with him.

4If his master gives him a wife and she gives birth to sons or daughters, the wife and her children belong to the master, and the slave must leave by himself.

5But if he makes this statement: ‘I hereby declare my love for my master, my wife, and my children. I don’t want to leave as a free man,’

6then his master must bring him to God. The master must bring him to the door or the doorframe and pierce his ear with an awl. Then he will be his slave for life.