Nahum 1:8

But with an overrunning flood - Bishop Newcome thinks this may refer to the manner in which Nineveh was taken. The Euphrates overflowed its banks, deluged a part of the city, and overturned twenty stadia of the wall; in consequence of which the desponding king burnt himself, and his palace, with his treasures. - Diodor. Sic., Edit. Wessel., p. 140, lib. ii., s. 27.

Darkness shall pursue - Calamity. All kinds of calamity shall pursue them till they are destroyed.