Following are a number of back-translations as well as a sample translation for translators of Numbers 23:21:

• Kupsabiny: “Pain/punishment is not coming to the stomach of Jacob,
  and the people of Israel is not getting suffering.
  Those people are together with their God,
  (they) are praising that king of theirs.” (Source: Kupsabiny Back Translation)
• Newari: “There is nothing bad for Jacob
  And there is no trouble for Israel.
  The LORD their God is with them,
  They have been proclaiming their king saying, ‘Long may [He] live!’” (Source: Newari Back Translation)
• Hiligaynon: “I have- not -seen disaster or hardship that will-come to Israel. The LORD their God is with them; they acknowledge him as their king.” (Source: Hiligaynon Back Translation)
• English: “Yahweh their God is with/helping them;
  they have declared that he is their true king.
  So the descendants of Jacob will not be harmed;
  they will not have any troubles.” (Source: Translation for Translators)