Isaiah 5
26 Ref And he will let a flag be lifted up as a sign to a far-off nation, whistling to them from the ends of the earth: and they will come quickly and suddenly.
27 Ref There is no weariness among them, and no man is feeble-footed: they come without resting or sleeping, and the cord of their shoes is not broken.
28 Ref Their arrows are sharp, and every bow is bent: the feet of their horses are like rock, and their wheels are like a rushing storm.