Rabbi Finley avoids any assessment of guilt in the narrative of Nadav and Avihu. As he reiterates, the Torah does not actually indicate why they performed this act, nor what they were thinking at the time. He observes that no one can be ready for when a seemingly minor infraction results in a disaster. The danger is in the slightest moment of inattention, that can have unforeseen consequences.
Matthew Berkowitz cites Samson Raphael Hirsch, who wrote that Nadav and Avihu acted only an individual members of the nation, without consulting either Aaron or Moses. In this regard they were selfish. He also cites Richard Elliot Friedman, who wrote that the standard for leaders is tougher than for others, and Aaron’s pain is a reminder of that.
Rabbi Sacks considers the striking tragedy of Aaron’s sons, Nadav and Avihu. He writes about the nature of holiness: a point of time and space in which the Presence of God is encountered by tzimtzum—self-renunciation—on the part of humankind. God’s Presence can only be experienced as absolute through the total renunciation of human will and initiative.