Following are a number of back-translations as well as a sample translation for translators of Jeremiah 21:13:

• Kupsabiny: “I hate you, oh city of Jerusalem. You were built on top of a hill so that you said, ‘Who is able to come and enter here where we live?’” (Source: Kupsabiny Back Translation)
• Hiligaynon: “I am against you (plur.), those from-Jerusalem, you (plur.) who are living/dwelling on the strong place in the valleys/plains on top of the mountain. You (plur.) boast saying, ‘We (incl.) will- not -be-harmed here! No one can-attack our (incl.) strong place!’” (Source: Hiligaynon Back Translation)
• English: “I will fight against you people of Jerusalem,
  you who live on top of a rocky hill above the valley.
  I will fight against you people who boast, saying,
  ‘No one can attack us and break through our defenses.’” (Source: Translation for Translators)