Kutoka 21 : 2 Exodus chapter 21 verse 2

Ukimnunua mtumwa wa Kiebrania, atakutumikia muda wa miaka sita; mwaka wa saba atatoka kwako huru bure.
soma Mlango wa 21

If you buy a Hebrew servant, he shall serve six years and in the seventh he shall go out free without paying anything.