Following are a number of back-translations as well as a sample translation for translators of Psalm 103:21:

• Chichewa Contempary Chichewa translation, 2002/2016:
  “Praise Jehovah, all heavenly creatures,
  you his servants who do his will.” (Source: Mawu a Mulungu mu Chichewa Chalero Back Translation)
• Newari:
  “Praise the LORD, O heavenly army,
  and His servants who do His will!” (Source: Newari Back Translation)
• Hiligaynon:
  “[You (plur.)] praise the LORD, all of you (plur.) his heavenly beings who serve him and obey his will.” (Source: Hiligaynon Back Translation)
• Laarim:
  “Praise the LORD, you the angels who are his soldiers,
  who worked for him, and do his will.” (Source: Laarim Back Translation)
• Nyakyusa-Ngonde (back-translation into Swahili):
  “Enyi majeshi yake, muwe mnamsifu BWANA,
  enyi watumishi wake, ambao mnafanya ambayo anapenda.” (Source: Nyakyusa Back Translation)
• English:
  “Praise Yahweh, you armies/ thousands of angels who serve him and do what he desires!” (Source: Translation for Translators)