The gates of the rivers shall be opened, and the palace shall be dissolved. The gates of the rivers shall be opened. The river wall on the Tigris (the west defense of Nineveh) was 4,530 yards long. On the north, south, and east sides there were large moats, capable of being easily filled with water from the Khosrsu. Traces of dams ("gates," or sluices) for regulating the supply are still visible, so that the whole city could be surrounded with a water barrier (Nahum 2:8, "Nineveh of old is like a pool of water"). Besides, on the east, the weakest side, it was further protected by a lofty double rampart, with a moat 200 feet wide between its two parts, cut in the rocky ground. The moats or canals, flooded by the Ninevites before the siege, to repel the foe, were made a dry bed to march into the city, by the foe turning the waters into a different channel, as Cyrus did in the siege of Babylon (Maurer). In the earlier capture of Nineveh by Arbaces the Mede, and Belesis the Babylonian, Diodorus Siculus, 50: 2,80, states that there was an old prophecy that it should not be taken until the river became its enemy; so, in the third year of the siege, the river, by a flood, broke down the walls twenty furlongs, and the king thereupon burnt himself and his palace, and all his concubines and wealth together, and the enemy entered by the breach in the wall. Fire and water were doubtless the means of the second destruction here foretold, as of the first.
And the palace shall be dissolved - by the inundation (Henderson). Or, those in the palace shall melt with fear-namely, the king and his nobles (Grotius).