Following are a number of back-translations as well as a sample translation for translators of Proverbs 26:28:

• Kupsabiny: “A person who is a liar hates people whom he speaks bad about,
  and the words of a person who flatters, destroys people.” (Source: Kupsabiny Back Translation)
• Newari: “The lying mouth will prove to be its own enemy.
  A flattering mouth will bring total destruction.” (Source: Newari Back Translation)
• Hiligaynon: “A liar man hates the people who are the victim of his lying.
  A man who flatters/insincerely-praises you (sing.) can-destroy you (sing.).” (Source: Hiligaynon Back Translation)
• Kankanaey: “A liar hates the one he speaks-badly-of. His flattering words are-destructive.” (Source: Kankanaey Back Translation)
• English: “Those who tell lies to others really hate them,
  and those who deceive others ruin them.” (Source: Translation for Translators)