Following are a number of back-translations as well as a sample translation for translators of Isaiah 8:9:

• Kupsabiny: “Oh, you nations far away,
  even if you gather/collect/muster your soldiers
  you shall not succeed.
  You shall prepare to come to fight
  but you shall be destroyed.” (Source: Kupsabiny Back Translation)
• Newari: “O nations! Cry out loudly to the people of the nations!
  Trembling, gather in one place. Listen,
  O people living in distant lands, be prepared to do battle, but take fear!
  Yes, really take fear.” (Source: Newari Back Translation)
• Hiligaynon: “You (plur.) nations, even if you (plur.) gather, you (plur.) will- still -spread-out. Listen you (plur.) who are at afar! Even if you (plur.) will-prepare for battle, you (plur.) will- still -be-defeated.” (Source: Hiligaynon Back Translation)
• English: “Listen, all you people in distant countries!
  You can prepare to attack Judah.
  You can prepare for battle, and shout your war-cries,
  but your armies will be crushed/shattered!” (Source: Translation for Translators)