Strange fire — Fire so called, because not taken from the altar, as it ought, but from some common fire. Before the Lord — Upon the altar of incense. Which he commanded not — Not commanding may be here put for forbidding, as it is, Jeremiah 32:35. Now as this was forbidden implicitly; Leviticus 6:12, especially when God himself made a comment upon that text, and by sending fire from heaven declared of what fire he there spake; so it is more than probable it was forbidden expressly, though that be not here mentioned, nor was it necessary it should be.
Related Commentaries of Leviticus 10:1
Leviticus 10:1
1 And Nadab and Abihu, the sons of Aaron, took either of them his censer, and put fire therein, and put incense thereon, and offered strange fire before the LORD, which he commanded them not.