Following are a number of back-translations as well as a sample translation for translators of Isaiah 5:21:

• Kupsabiny: “(They) are badly off
  those people who take themselves to be wise
  and see themselves as knowledgeable.” (Source: Kupsabiny Back Translation)
• Newari: “Alas to those who think that they are wise in their own eyes
  and who think that they are clever in their own eyes.” (Source: Newari Back Translation)
• Hiligaynon: “You (plur.) are-to-be-pitied who think that you (plur.) are wise and clever/[lit. brainy].” (Source: Hiligaynon Back Translation)