Following are a number of back-translations as well as a sample translation for translators of Psalm 78:21:

• Chichewa Contempary Chichewa translation, 2002/2016:
  “When Jehovah heard them he became very angry?
  his fire burned against Jacob,
  and his anger rose against Israel,” (Source: Mawu a Mulungu mu Chichewa Chalero Back Translation)
• Newari:
  “Hearing this the LORD became angry,
  and seeing the descendants of Jacob, fire broke out.
  Seeing them His anger became more intense.” (Source: Newari Back Translation)
• Hiligaynon:
  “So God got-angry when he heard them.
  In his anger with them who (were) Israelites, who (were) the descendants of Jacob, he attacked them with fire.” (Source: Hiligaynon Back Translation)
• Laarim:
  “When the LORD heard them, he became very angry,
  his fire came to burn the people of Jacob,
  his anger arose against the people of Israel,” (Source: Laarim Back Translation)
• Nyakyusa-Ngonde (back-translation into Swahili):
  “BWANA wakati amesikia, akachukia sana,
  moto ukawawakia wa jamaa ya Yakobo.
  Hasira zake zikawainukia waisraeli.” (Source: Nyakyusa Back Translation)
• English:
  “So, when Yahweh heard that, he became very angry,
  and he sent a fire to burn up some of his Israeli people.” (Source: Translation for Translators)