Eleazar and Ithamar ministered—in the sight of Aaron their father— See Numbers 3:38. In the sight of their father, means, most probably, together with their father.
Related Commentaries of Numbers 3:4
Numbers 3:4
4 And Nadab and Abihu died before the LORD, when they offered strange fire before the LORD, in the wilderness of Sinai, and they had no children: and Eleazar and Ithamar ministered in the priest's office in the sight of Aaron their father.