And that night the angel of the LORD went out and struck down 185,000 in the camp of the Assyrians. And when people arose early in the morning, behold, these were all dead bodies.
Sometimes it was long ere prophecies were accomplished and promises performed; but here the word was no sooner spoken than the work was done. I. The army of Assyria was entirely routed. That night which immediately followed the sending of this message to Hezekiah, when the enemy had just set down before the city and were preparing (as we now say) to open the trenches...
Commenting on 2 Kings 19:35-37
AN ANGEL DESTROYS THE ASSYRIANS. (Kg2 19:35-36) in the morning . . . they were all dead corpses--It was the miraculous interposition of the Almighty that defended Jerusalem. As to the secondary agent employed in the destruction of the Assyrian army, it is most probable that it was effected by a hot south wind, the simoon, such as to this day often envelops and destroys whole caravans.
That night - The very night after the blasphemous message had been sent, and this comfortable prophecy delivered. The angel of the Lord went out - I believe this angel or messenger of the Lord was simply a suffocating or pestilential Wind; by which the Assyrian army was destroyed, as in a moment, without noise confusion or any warning. See the note Kg1 20:30.