Following are a number of back-translations as well as a sample translation for translators of Zephaniah 3:9:

• Kupsabiny: “On that day I shall cleanse the heads of all people so that every person shall worship me and work for me with one stomach.” (Source: Kupsabiny Back Translation)
• Newari: “‘At that time I will make pure the lips of the people of the nation,
  so that they will all take on the name of the LORD,
  and to serve one mind for Him.” (Source: Newari Back Translation)
• Hiligaynon: “And then I will-renew the people so-that all of them will-take-refuge in me and will-be-one in serving me.” (Source: Hiligaynon Back Translation)
• English: “When that happens, I will cause all people to be changed
  and enable them to speak only what is pure/pleasing to me,
  in order that everyone can worship me
  and unitedly/together serve me.” (Source: Translation for Translators)