Following are a number of back-translations as well as a sample translation for translators of Isaiah 50:10:

• Kupsabiny: “Who among you obeys God
  and honors the words of his servant?
  Anyone who goes through a path of darkness must
  trust in his God.” (Source: Kupsabiny Back Translation)
• Newari: “Who among you fears the LORD,
  and obeys the words of his servant?
  Those who go in dark places without light,
  put your hope in the name of the LORD and trust in your God.” (Source: Newari Back Translation)
• Hiligaynon: “Who among you (plur.) respect the LORD and obey what his servant is teaching? He should rely/trust on the LORD his God even if he walks in darkness which has no [intensifier] light.” (Source: Hiligaynon Back Translation)
• English: “If you revere Yahweh
  and do what his servant tells you to do,
  even if you are walking in darkness/enduring suffering, and it seems that there is no light,
  trust in Yahweh your God to help you.” (Source: Translation for Translators)