1 Kings 18:38 - Joseph Benson’s Commentary on the Old and New Testaments

The fire of the Lord fell And not only, as at other times, (see the margin,) consumed the sacrifice and the wood, in token of God's acceptance of the offering, but licked up all the water that was in the trench, exhaling and drawing it up as a vapour, to descend (with other water, to be raised from the adjoining sea) in the intended rain, which was to be the fruit of this sacrifice and prayer, more than the product of natural causes. And this was not all. To complete the miracle, the fire consumed the stones of the altar, and the very dust, to show that it was no ordinary fire, and perhaps to intimate that though God accepted this occasional sacrifice from this altar, yet for the future they ought to demolish all the altars on their high places, and for their constant sacrifices make use of that at Jerusalem only. Moses's altar and Solomon's were consecrated by fire from heaven; but this was destroyed, because it was to be used no more. We may well imagine, what a terror this fire struck on guilty Ahab, and all the worshippers of Baal, and how they fled from it as far and as fast as they could, saying, in their hearts, Lest it consume us also, Numbers 16:34.