Following are a number of back-translations as well as a sample translation for translators of Proverbs 12:23:

• Kupsabiny: “A wise person does not show how big his knowledge is,
  but the fool tells out/exposes his foolishness.” (Source: Kupsabiny Back Translation)
• Newari: “Wise people do not show off
  their skill and learning.
  But fools display their foolishness.” (Source: Newari Back Translation)
• Hiligaynon: “A wise man does not boast what he knows, but a fool man he surely shows his foolishness.” (Source: Hiligaynon Back Translation)
• Kankanaey: “The careful/circumspect, he does not relate what he knows, but the foolish-one, he talk-loudly-about what is useless.” (Source: Kankanaey Back Translation)
• English: “Those with good sense do not reveal all that they know;
  foolish people show clearly by what they say that they are ignorant/have not learned much.” (Source: Translation for Translators)