Isaiah 21:7-9

7When he sees riders — pairs of horsemen, riders on donkeys, riders on camels — he must pay close attention.”

8Then the lookout reported, “Lord, I stand on the watchtower all day, and I stay at my post all night.

9Look, riders come — horsemen in pairs.” And he answered, saying, “Babylon has fallen, has fallen. All the images of her gods have been shattered on the ground.”