Following are a number of back-translations as well as a sample translation for translators of Isaiah 9:18:

• Kupsabiny: “Please, sins are like a fire
  that burns brightly to destroy thorns and bush.
  It burns like a fire in a forest,
  and it gives smoke that rises going up to the sky.” (Source: Kupsabiny Back Translation)
• Newari: “Surely, wickedness will burn like fire
  by which briers and thorns are reduced to ashes.
  The underbrush of the forest is kindled by it,
  and spreads upward as columns of smoke.” (Source: Newari Back Translation)
• Hiligaynon: “For their wickedness are like a fire that burns the thorny bushes. It is burning like a fire that burns a forest, and the thick smoke rising upward.” (Source: Hiligaynon Back Translation)
• English: “There are glorious forests and fertile farmlands in Assyria, but I will completely destroy them;
  they will be like a very sick person who shrivels up and then dies.” (Source: Translation for Translators)