Following are a number of back-translations as well as a sample translation for translators of Isaiah 66:16:

• Kupsabiny: “He shall punish them with fire
  and destroy them with his sword.
  The people are many whom God will destroy.” (Source: Kupsabiny Back Translation)
• Newari: “The LORD will judge all people by fire and the sword,
  and there will be many who die by the LORD.” (Source: Newari Back Translation)
• Hiligaynon: “For by-means of the fire and his sword, the LORD will-punish all the people who are sinners, and he will-kill many.” (Source: Hiligaynon Back Translation)
• English: “It is as though Yahweh has a big sword,
  and he will judge and execute many people.” (Source: Translation for Translators)