God had consecrated Aaron and his sons to the holy vocation of the priesthood. It was in the context of their priestly service that two of Aaron’s four sons, Nadab and Abihu, each got a censer—a kind of vessel that was used in antiquity to contain the incense that was burned as an offering before God—put fire in them, put incense on them, and offered what the book of Leviticus calls “unauthorized fire.” What is “unauthorized fire,” or, as it is rendered in other translations, “profane fire” or “strange fire”?