Kutoka 4 : 23 Exodus chapter 4 verse 23

nami nimekuambia, Mpe mwanangu ruhusa aende, ili apate kunitumikia, nawe umekataa kumpa ruhusa aende; angalia basi, mimi nitamwua mwanao, mzaliwa wa kwanza wako.
soma Mlango wa 4

and I have said to you, "Let my son go, that he may serve me;" and you have refused to let him go. Behold, I will kill your son, your firstborn.'"