Following are a number of back-translations as well as a sample translation for translators of Isaiah 21:9:

• Kupsabiny: “I see young men who come with/on horses
  going two by two.’
  Then (he) said,
  ‘Babylon has fallen!
  The things (they) were worshipping are spread/scattered all over.’” (Source: Kupsabiny Back Translation)
• Newari: “Look! one person is coming in a chariot with a team of horses.
  And speaking like this he gave answer:
  ‘Babylon has been destroyed,
  Its carved idols have gone to pieces and are falling to the ground.’"” (Source: Newari Back Translation)
• Hiligaynon: “And now, look! There are chariots and horse-riders in pairs that are-coming.’ Then the guard still said, ‘Babilonia is destroyed now! All images of her little-gods/false-gods are on the ground and all are broken.’” (Source: Hiligaynon Back Translation)
• English: “Now, I saw a man riding in a chariot pulled by two horses.
  I called out to him, and he answered/shouted,
  ‘Babylon has been destroyed!
  All the idols in Babylon lie in pieces on the ground!’’” (Source: Translation for Translators)