Following are a number of back-translations as well as a sample translation for translators of Isaiah 55:13:

• Kupsabiny: “Podo trees shall grow where there are thornbushes today,
  and myrtles shall grow where there are thorns.
  This word will become a word by which God is remembered/thought about.
  This is a sign that stays forever
  and it will never be thrown away/discarded.” (Source: Kupsabiny Back Translation)
• Newari: “After that, instead of thorn bushes, trees of cypress wood [will begin to sprout],
  and instead of nettle plants, myrtle trees will begin to sprout.
  In this way there will be honor for the LORD.
  This will be an eternal [lit.: for forever forever] sign that will never be destroyed."” (Source: Newari Back Translation)
• Hiligaynon: “Sipres and mirto trees will-grow where thorny bushes now grow. These happenings will-give honor to me; it will-be a sign of my greatness forever/[lit. until whenever].’” (Source: Hiligaynon Back Translation)