And it came to pass that night, that the angel of the LORD went out, and smote in the camp of the Assyrians an hundred fourscore and five thousand: and when they arose early in the morning, behold, they were all dead corpses. 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 1 Kings 20:30. Thus was the threatening, 2 Kings 19:7, fulfilled, I will send a Blast upon him; for he had heard the rumor that his territories were invaded; and on his way to save his empire, in one night the whole of his army was destroyed, without any one even seeing who had hurt them. This is called an angel or messenger of the Lord: that is, something immediately sent by him to execute his judgments.
When they arose early - That is, Sennacherib, and probably a few associates, who were preserved as witnesses and relaters of this most dire disaster. Rab-shakeh, no doubt, perished with the rest of the army.