Following are a number of back-translations as well as a sample translation for translators of Isaiah 43:12:

• Kupsabiny: “I showed what was going to happen,
  and then I saved you.
  There is no god/idol of other communities
  who has done things like this for you.
  You yourselves know I am speaking the truth.” (Source: Kupsabiny Back Translation)
• Newari: “I have predicted what would happen, delivered and proclaimed —
  I am the one who has done this among you, not foreign god."
  The LORD Almighty has said, "You are witness that I indeed am God.” (Source: Newari Back Translation)
• Hiligaynon: “I alone who prophesied that you (plur.) will-be-saved, and I fulfilled it. There is no other god who have-done this to you (plur.); you (plur.) are my witnesses.
  The LORD still said, ‘I am God.” (Source: Hiligaynon Back Translation)