Isaiah 21
7 Ref and when he seeth a troop, horsemen in pairs, a troop of asses, a troop of camels, he shall hearken diligently with much heed.
8 Ref And he cried as a lion: O Lord, I stand continually upon the watch-tower in the day-time, and am set in my ward whole nights;
9 Ref and, behold, here cometh a troop of men, horsemen in pairs. And he answered and said, Fallen, fallen is Babylon; and all the graven images of her gods are broken unto the ground.