Following are a number of back-translations as well as a sample translation for translators of Isaiah 58:1:

• Kupsabiny: “God is saying,
  ‘Shout (sing.) loudly and do not rest!
  Shout loud to sound like a horn
  and tell to my people their mistakes,
  for the stomach of Jacob to know their evil.” (Source: Kupsabiny Back Translation)
• Newari: “Shout loudly, do not remain silent!
  Shout loudly like the sound of a trumpet!
  Show my people that they are rebellious
  and show the clan of Jacob their sin.” (Source: Newari Back Translation)
• Hiligaynon: “The LORD says, ‘[You (plur.)] shout loudly like the loud-sound of a trumpet! You (plur.) do not hold it! Tell/declare to my people who are the descendants of Jacob their sins and trespasses.” (Source: Hiligaynon Back Translation)
• English: “Yahweh said to me,
  ‘Shout loudly!
  Shout like a loud trumpet!
  Shout to warn my Israeli people about their sins !” (Source: Translation for Translators)