Kumbukumbu la Torati 21 : 16 Deuteronomy chapter 21 verse 16

ndipo itakapokuwa ya kwamba siku atakayowarithisha wanawe alivyo navyo, asimweke mwana wa ampendaye kuwa mzaliwa wa kwanza mbele ya mwana wa asiyempenda, naye ndiye mzaliwa wa kwanza huyu;
soma Mlango wa 21

then it shall be, in the day that he causes his sons to inherit that which he has, that he may not make the son of the beloved the firstborn before the son of the hated, who is the firstborn: