Following are a number of back-translations as well as a sample translation for translators of Jeremiah 8:9:

• Kupsabiny: “Those who take themselves to be wise will be put to shame
  they are confused and trapped.
  As they have refused the word of God,
  what kind of wisdom do they think that they have?” (Source: Kupsabiny Back Translation)
• Hiligaynon: “Those who considered themselves wise will- surely -be-put-to-shame. They will-be- very -afraid for they will-be-taken-captive, because they rejected my words. So, are they truly wise?” (Source: Hiligaynon Back Translation)
• English: “Those teachers, who think that they are wise, will be ashamed/disgraced and dismayed when they are taken to other countries by their enemies
  because they sinned by rejecting what I told them.
  Truly, they were not very wise to do that!” (Source: Translation for Translators)