Yeremia 34 : 9 Jeremiah chapter 34 verse 9

ya kwamba kila mtu amweke huru mtumwa wake, na kila mtu amweke huru mjakazi wake, ikiwa yule mwanamume au yule mwanamke ni Mwebrania; mtu ye yote asiwatumikishe, yaani, asimtumikishe Myahudi, nduguye;
soma Mlango wa 34

that every man should let his man-servant, and every man his maid-servant, who is a Hebrew or a Hebrewess, go free; that none should make bondservants of them, [to wit], of a Jew his brother.