Following are a number of back-translations as well as a sample translation for translators of Numbers 21:28:

• Kupsabiny: “Fire came from Heshbon,
  a fire that came from the city of Sihon.
  The fire consumed the city of Ar in Moab,
  and ate the mountains of Arnon.” (Source: Kupsabiny Back Translation)
• Newari: “Fire came out from Heshbon,
  A torch came out from the city of Sihon.
  By it the city of Ar of the land of Moab [and]
  the people in the Arnon river heights [lit.: in the place high above the Arnon river] were reduced to ashes. ” (Source: Newari Back Translation)
• Hiligaynon: “That (is) why the poets says,
  ‘[You (plur.)] come to Heshbon, the city of Sihon, and [you (plur.)] build it again. Formerly the soldiers of Heshbon attacked like a blazing fire and devoured the town of Ar which is under-the-jurisdiction of Moab and destroyed the high places of Arnon.” (Source: Hiligaynon Back Translation)
• English: “A fire blazed from Heshbon;
  it burned down Ar city in Moab,
  it destroyed everything on the hills along the Arnon River.” (Source: Translation for Translators)