Following are a number of back-translations as well as a sample translation for translators of Isaiah 57:8:

• Kupsabiny: “You have placed there at the doorposts
  your things that you worship.
  So you commit adultery refusing me
  when you bring those things into the house and worship (them).
  You spread/prepare your beds
  and sleep with those things that you worship.
  You agree with them what you give (to (them)
  and you desire to sleep with them.” (Source: Kupsabiny Back Translation)
• Newari: “On your gate and behind the entrance of the door,
  you have put symbols that honor other religions.
  Having abandoned me, you have taken off your clothes,
  laid down and invited many to your bed.
  You have sealed a covenant with them, and you are loving their bed,
  for you have loved to look at their naked [bodies].” (Source: Newari Back Translation)
• Hiligaynon: “You (plur.) even put/place the images of your (plur.) little-god at the door side of your (plur.) houses. You (plur.) reject me; you (plur.) are like a woman who commits-adultery-with-a-man who climbed into the wide bed, who just agrees that they will-lie-down-beside/(will-have-sexual-relations-with) with her lover. She really likes to have-sex with her another-man/[lit. male]; she satisfies her lust.” (Source: Hiligaynon Back Translation)