Nadab and Abihu were punished by death in the Lord’s presence (see Leviticus 10:1–20). Nadab is mentioned here as Aaron’s firstborn,
perhaps to remind the reader of the rights that God has over the firstborn in Israel (see Exodus 13:14–16). In particular, it shows that Nadab’s disobedience and the discipline incurred thereby did not change his status as firstborn,
nor did it in any way diminish the office to which he had been appointed. The punishment that Aaron’s firstborn received only serves to confirm the holiness of the office to which he had been appointed.
2 These are the names of the sons of Aaron: Nadab the firstborn, and Abihu, Eleazar, and Ithamar.