Following are a number of back-translations as well as a sample translation for translators of Isaiah 66:14:

• Kupsabiny: “You shall see these things and your stomachs/hearts shall rejoice.
  Your bodies shall be well/healthy and you shall find strength.
  Then, it shall be seen again that God is helping his servants
  and is angry with his enemies.” (Source: Kupsabiny Back Translation)
• Newari: “You will see this and your heart will rejoice greatly.
  And you will flourish like grass.
  The hand of the LORD will proceed towards his servants,
  His anger, however, will be seen moving towards the enemies.” (Source: Newari Back Translation)
• Hiligaynon: “When you (plur.) see this, you (plur.) will- really -be-glad, and you (plur.) will-be-strengthened like a flourishing plant. The LORD will-show his power to his servants, but he will-show his wrath to-(against) his enemies.” (Source: Hiligaynon Back Translation)
• English: “When you see those things happen,
  you will rejoice.
  Your old bones will become strong again
  like grass that grows quickly/well in the springtime.
  When that happens, everyone will know that Yahweh has power to help those who worship and obey him,
  but that he is angry with his enemies.” (Source: Translation for Translators)