Following are a number of back-translations as well as a sample translation for translators of Isaiah 28:20:

• Kupsabiny: “The bed shall become short
  so that a person cannot sleep it it.
  The blanket shall become small
  so that a person cannot cover himself with it.” (Source: Kupsabiny Back Translation)
• Newari: “The cot will be [too] short for you to lie down on,
  and the blanket will also be too narrow.” (Source: Newari Back Translation)
• Hiligaynon: “For you (plur.) are like a man whose something-he-lays-on is too short and his blanket is too narrow.” (Source: Hiligaynon Back Translation)
• English: “You have heard people say, ‘Your bed is very short, you will not be able to sleep in it;
  your blankets are very narrow; they will not cover you!’
  That means for you that your agreement with Egypt is not going to save you.” (Source: Translation for Translators)