Then Sennacherib, king of Assyria, went away and returned. He now shows how disgraceful was the retreat of this haughty tyrant, who in the wishes of his heart had already devoured the whole of Judea, and formerly dared to pretend to be more powerful than God himself. By employing a variety of words to express his departure, the Prophet indirectly censures the shameful flight; for the repetition is not superfluous, "He set out, he went away, he returned." The title of king is added for the sake of greater disgrace. "Lo, this is the great king of whose power Rabshakeh boasted so highly." And dwelt in Nineveh. He did not come into Judea, that: he might depart from it in that disgraceful manner; and therefore the hand of God throws him back, even as straw is driven by the wind. The circumstance of his dwelling in Nineveh reminds us also that he had lost his courage as well as his forces; for he would not willingly have remained at rest, if despair had not held him like a chain. This means, therefore, that he was satisfied with his ancient domains, of which Nineveh was the chief city and royal residence. At a later period, when the Assyrians were conquered by the Chaldeans, the seat of government was removed to Babylon, that is, ten years after the death of Sennacherib, and during the reign of Esarhaddon, his successor, who is here mentioned, for since parricides did not want defenders, a nation torn by factions was easily subdued and conquered by foreign enemies. Availing himself of this opportunity, Merodach invaded the Assyrians, and subjected them to his power.

So Sennacherib departed - Probably with some portion of his army and retinue with him, for it is by no means probable that the whole army had been destroyed. In 2-Chronicles 32:21, it is said that the angel 'cut off all the mighty men of valor, and the leaders and captains in the camp of the king of Assyria.' His army was thus entirely disabled, and the loss of so large a part of it, and the consternation produced by their sudden destruction, would of course lead him to abandon the siege.
Went and returned - Went from before Jerusalem and returned to his own land.
And dwelt at Nineveh - How long he dwelt there is not certainly known. Berosus, the Chaldean, says it was 'a little while' (see Joshua. Ant. x. 1. 5). Nineveh was on the Tigris, and was the capital of Assyria. For an account of its site, and its present situation, see the American Biblical Repository for Jan. 1837, pp. 139-159.

So Sennacherib king of Assyria departed, and went and returned, and dwelt at (c) Nineveh.
(c) Which was the chiefest city of the Assyrians.

So Sennacherib king of Assyria departed, and went, and returned,.... Being informed of the destruction of his army in this miraculous manner, he departed from the place where he was in all haste, fearing lest he himself should be destroyed in like manner; and having no forces to pursue his designs, or wherewith to make an attempt elsewhere, he made the best of his way at once into his own country, whither he returned with great shame and confusion:
and dwelt at Nineveh; the metropolis of his kingdom; see Genesis 10:11.

dwelt at Nineveh--for about twenty years after his disaster, according to the inscriptions. The word, "dwelt," is consistent with any indefinite length of time. "Nineveh," so called from Ninus, that is, Nimrod, its founder; his name means "exceedingly impious rebel"; he subverted the existing patriarchal order of society, by setting up a system of chieftainship, founded on conquest; the hunting field was his training school for war; he was of the race of Ham, and transgressed the limits marked by God (Genesis 10:8-11, Genesis 10:25), encroaching on Shem's portion; he abandoned Babel for a time, after the miraculous confusion of tongues and went and founded Nineveh; he was, after death, worshipped as Orion, the constellation (see on Job 9:9; Job 38:31).