Leviticus 10:1-3

Aaron’s sons Nadab and Abihu took their pans for burning incense, put fire in them, and added incense; but they did not use the special fire Moses had commanded them to use in the presence of the LORD. So fire came down from the LORD and destroyed Nadab and Abihu, and they died in front of the LORD. Then Moses said to Aaron, “This is what the LORD was speaking about when he said, ‘I must be respected as holy by those who come near me; before all the people I must be given honor.’ ” So Aaron did not say anything about the death of his sons.