2 Kings 19:35

The camp of the Assyrians - Which was now moved to Pelusium, if we may trust Herodotus; or which, at any rate, was at some considerable distance from Jerusalem.

When they arose early in the morning, behold ... - These words form the only trustworthy data that we possess for determining to any extent the manner of the destruction now worked. They imply that there was no disturbance during the night, no alarm, no knowledge on the part of the living that their comrades were dying all around them by thousands. All mere natural causes must be rejected, and God must be regarded as having slain the men in their sleep without causing disturbance, either by pestilence or by that “visitation” of which English law speaks. The most nearly parallel case is the destruction of the first-born, Exodus 12:29.

The Egyptian version of this event recorded in Herodotus is that, during the night, silently and secretly, an innumerable multitude of field-mice spread themselves through the Assyrian host, and gnawed their quivers, bows, and shield-straps, so as to render them useless. When morning broke, the Assyrians fled hastily, and the Egyptians pursuing put a vast number to the sword.