Following are a number of back-translations as well as a sample translation for translators of Jeremiah 6:26:

• Kupsabiny: “God is saying to his people,
  ‘Put on sacks
  and roll yourselves in ashes.
  Scream loudly and mourn/grieve
  like a person who mourns his/her only child,
  because the destroyer will suddenly come upon you to fight against you.” (Source: Kupsabiny Back Translation)
• Hiligaynon: “Fellowmen, cloth yourself with sackcloth and roll in ashes to show your (plur.) mourning. You (plur.) mourn bitterly as-if your (plur.) only male child/(son) died. For suddenly the enemy will-attack us (incl.).” (Source: Hiligaynon Back Translation)
• English: “So I say, ‘My dear people, put on sackcloth/rough clothes and sit in ashes to show that you are sorry for your sins.
  Mourn and cry very much,
  like a woman would cry if her only son had died,
  because your enemies are very near,
  and they are going to destroy everything.’” (Source: Translation for Translators)