Following are a number of back-translations as well as a sample translation for translators of Isaiah 48:21:

• Kupsabiny: “Thirst did not disturb them in the desert
  when God led them along.
  God made water come out from a rock for those people.
  He opened the rock for water to gush out.’” (Source: Kupsabiny Back Translation)
• Newari: “When the LORD led his people, going through the wilderness,
  they did not feel thirsty.
  He brought out water for them from a big rock.
  He split the big rock in two,
  and from there, water came out.” (Source: Newari Back Translation)
• Hiligaynon: “They did not get-thirst when God led them through the deserts, for he caused- the water -to-flow out-of the rock for them. He split the rock and the water gushed-out.” (Source: Hiligaynon Back Translation)