Aaron’s four sons were the anointed priests, but he lost two of them. “But Nadab and Abihu died before the LORD when they offered unauthorized fire before the LORD in the wilderness of Sinai, and they had no children. So Eleazar and Ithamar served as priests in the lifetime of Aaron their father.” (Numbers 3:4) The event is also mentioned in Leviticus 10:1-2. In neither place are we told what this “unauthorized fire” was exactly. Some translations call it “strange fire”….