John Gill Commentary Numbers 3:2

"And these are the names of the sons of Aaron: Nadab the first-born, and Abihu, Eleazar, and Ithamar." — Numbers 3:2 (ASV)

And these [are] the names of the sons of Aaron
The Targum of Jonathan adds, disciples of Moses, the master of the Israelites; none of the posterity of Moses being expressly, named; Jarchi observes, that the sons of Aaron are called the generations of Moses, because he taught them the law; for whoever, he says, teaches his neighbour's son, the law, the Scripture accounts of him as if he begat him, see (1 Corinthians 4:15) ;

Nadab the firstborn, and Abihu, Eleazar and Ithamar ;
as in (Exodus 6:23) .