Throughout Leviticus 8:1 – 9:24 the phrase, “Just as the Lord had commanded” emphasized the obedience required by the priesthood. Now the reader is told that Nadab and Abihu did that, “which he had not commanded them.” Nadab and Abihu drew near to God in a disrespectful manner, one that is not in accordance with his Word. It is, therefore, a deliberate disobedience.
1 Les fils d'Aaron, Nadab et Abihu, prirent chacun un brasier, y mirent du feu, et posèrent du parfum dessus; ils apportèrent devant l'Eternel du feu étranger, ce qu'il ne leur avait point ordonné.