Nadab and Abihu died before YHWH when they offered strange fire before YHWH in the wilderness of Sinai, and they had no children. Eleazar and Ithamar ministered in the priest’s office in the presence of Aaron their father.
But bring your brothers, the tribe of Levi, the tribe of your father, so that they joined you and minister to you, while you and your sons with you are before the Tent of the Testimony.
Yet they may be ministers in my sanctuary, having oversight at the gates of the house, and ministering in the house. They may slaughter the burnt offering and the sacrifice for the people and stand before them to minister to them.
and Aaron is to present the Levites before YHWH for a wave offering on the behalf of the children of Israel, that it may be theirs to do the service of YHWH.
