Following are a number of back-translations as well as a sample translation for translators of Proverbs 29:24:

• Kupsabiny: “A person who eats with (joins) thieves will just stab himself,
  because even though he swears an oath, he will not tell the truth.” (Source: Kupsabiny Back Translation)
• Newari: “The one who helps a thief becomes his own enemy.
  Even if he does give true testimony
  he will still have to bear the punishment.
  and if he does not give [true testimony]
  he will still have to bear God’s curse.” (Source: Newari Back Translation)
• Hiligaynon: “A person who is a accomplice of a thief harms him/herself. Even-though he/she has-been-asked-to-swear to tell the truth, he/she will- never -tell.” (Source: Hiligaynon Back Translation)
• Kankanaey: “The one who companions-with a thief, it-is-as-if he hates his very self (lit. his body just the same), because even though they have-him-swear to testify, he will not tell the truth.” (Source: Kankanaey Back Translation)
• English: “Those who help thieves to steal only hurt themselves;
  when they are in court, they solemnly ask God to curse them if they do not tell the truth,
  but they do not tell the truth about the crime that was committed,
  and as a result, God will curse them.” (Source: Translation for Translators)