John Gill Commentary 2 Kings 1:10

"And Elijah answered and said to the captain of fifty, If I be a man of God, let fire come down from heaven, and consume thee and thy fifty. And there came down fire from heaven, and consumed him and his fifty." — 2 Kings 1:10 (ASV)

And Elijah answered and said to the captain of fifty, if I be a man of God As I am, and you shall know it by the following token, though you call me so jeeringly: then let fire come down from heaven, and consume you and your fifty ; this he said not in a passion, and from a private spirit of revenge, but for the vindication of the honour and glory of God, and under the impulse of his spirit, who was abused through the insult on him as his prophet: and there came down fire from heaven, and consumed him and his fifty ; a flash of lightning, which destroyed them at once; the Lord hearkening to the voice of his prophet, in vindication of him in his office, and of his own glory.