Following are a number of back-translations as well as a sample translation for translators of Proverbs 10:21:

• Kupsabiny: “The words of the righteous strengthens/encourages many people
  but those who are fools die because (they) do not listen to words.” (Source: Kupsabiny Back Translation)
• Newari: “The words of the righteous
  are a help to many,
  fools die because of their own [fool’s] wisdom.” (Source: Newari Back Translation)
• Hiligaynon: “The word of a righteous man can-give goodness to many people aside from the foolish-ones who will-die because they do not have understanding.” (Source: Hiligaynon Back Translation)
• Kankanaey: “Many are helped because of the advice of the righteous/just, but the foolish will die since they are mindless (lit. have no minds/thoughts).” (Source: Kankanaey Back Translation)
• English: “What righteous people say benefits many people,
  but foolish people die because of the stupid things that they do.” (Source: Translation for Translators)