Exodus 21:2-4

“If you purchase a Hebrew servant [because of his debt or poverty], he shall serve six years, and in the seventh [year] he shall leave as a free man, paying nothing. [Lev 25:39] If he came [to you] alone, he shall leave alone; if he came married, then his wife shall leave with him. If his master gives him a wife, and she gives birth to sons or daughters, the wife and her children shall belong to her master, and he shall leave [your service] alone.