Following are a number of back-translations as well as a sample translation for translators of Isaiah 28:15:

• Kupsabiny: “You boast that you have made an agreement with death
  and you have agreed with the world of the dead.
  You are saying that even if death/disaster comes
  nothing shall happen to you.
  You shall be destroyed because you are trusting in a lie
  and protected yourselves with deception.” (Source: Kupsabiny Back Translation)
• Newari: “You speak arrogantly like this, "We have sealed an agreement with death,
  and made a promise with the grave.
  Even if a very great disaster comes to our place,
  we cannot be touched by it.
  For we have taken shelter in the false words that we speak,
  and we have made falsehood a hiding place."” (Source: Newari Back Translation)
• Hiligaynon: “For you (plur.) are-boasting saying, ‘We (excl.) have-made a covenant with death that this would- not -harm us (excl.), and we (excl.) have-agreed with the place of the dead-ones that we (excl.) would- not -be-brought there. Therefore we (excl.) will- not -be-harmed even disaster will-come like a flood, for we (excl.) trust that our (excl.) lying and deceiving can-protect us (excl.).’” (Source: Hiligaynon Back Translation)