Following are a number of back-translations as well as a sample translation for translators of Isaiah 48:19:

• Kupsabiny: “Your descendants would have been many
  like the sand of the ocean.
  Your grandchildren would not have been destroyed
  and killed in front of you.” (Source: Kupsabiny Back Translation)
• Newari: “Your descendants would have been like sand,
  and your sons and daughters would have uncountable.
  their names would never have been removed from me,
  and they would not have been destroyed before me."” (Source: Newari Back Translation)
• Hiligaynon: “Wish-that your (plur.) descendants would-become as many as the sand which can- not -be-counted, and they will- never -be-destroyed before me.’” (Source: Hiligaynon Back Translation)