Following are a number of back-translations as well as a sample translation for translators of Jeremiah 51:11:

• Kupsabiny: “God has stirred up the kings of Medes/Media,
  because he wants to destroy Babylon.
  He will pay back like that,
  because that country destroyed the House of God.
  The leaders of the soldiers are saying to the young men of war,
  ‘Sharpen your arrows.
  Fill (plur.) the quiver with arrows.” (Source: Kupsabiny Back Translation)
• Hiligaynon: “The LORD will take-vengeance to Babilonia because of her destroying his temple. The LORD challenged the kings of Media to destroy Babilonia for this is his purpose. He said, ‘Sharpen your arrows and get-ready your shields.” (Source: Hiligaynon Back Translation)
• English: “You enemy soldiers, sharpen your arrows!
  Lift up your shields,
  because Yahweh has incited your kings of Media and Persia to march with their armies to Babylon and to destroy it.
  That is how Yahweh will get revenge on those foreigners who entered his temple in Jerusalem and defiled it.” (Source: Translation for Translators)