You shall put them on Aaron your brother and on his sons with him; and you shall anoint them and ordain them and set them apart as holy, that they may minister to Me as priests.
and you shall anoint them even as you have anointed their father, that they may minister as priests to Me; and their anointing will be for them for a perpetual priesthood throughout their generations.”
So Moses took some of the anointing oil and some of the blood which was on the altar and sprinkled it on Aaron, on his garments, on his sons, and on the garments of his sons with him; and he set Aaron apart as holy, his garments and his sons and the garments of his sons with him.
But Nadab and Abihu died before Yahweh when they offered strange fire before Yahweh in the wilderness of Sinai; and they had no children. So Eleazar and Ithamar ministered as priests in the lifetime of their father Aaron.
For the Law appoints men as high priests who are weak, but the word of the oath, which came after the Law, appoints a Son, who has been made perfect forever.