Following are a number of back-translations as well as a sample translation for translators of Zechariah 13:9:

• Kupsabiny: “I shall bring these few through fire and cleanse (them)
  like silver and gold is cleansed through fire.
  They will cry to me then/there
  and I shall respond to/answer their prayers.
  I shall say, ‘These people are mine’
  and they, too, shall say, ‘God is ours.’ ’” (Source: Kupsabiny Back Translation)
• Newari: “To test the remaining third,
  I will refine them, as fire refines silver.
  I will refine them like gold is refined,
  at that time they will call on my name.
  And I will answer them.
  I will say, ‘these are my people.’
  And they will say, ‘the LORD is our God.’"” (Source: Newari Back Translation)
• Hiligaynon: “The third part that (is) left I will-clean them like silver that is-purified by fire. And I will-test them like gold that is-tested by fire if (it is) pure or not. They will-pray to me and I will-listen to them. I will-say, ‘They (are) my people,’ and they will-say, ‘The LORD (is) our (excl.) God.’ ’” (Source: Hiligaynon Back Translation)
• English: “And I will test the ones that remain alive by causing them to experience great difficulties, to find out if they will continue to worship me.
  I will purify them like a man purifies gold or silver by putting it into a very hot fire.
  Then my people will call to me for help,
  and I will answer them.
  I will say to them, ‘You are my people,’
  and they will say, ‘Yahweh is our God.’ ’” (Source: Translation for Translators)