ٱلْأَنْبِيَاء : ٣٩

  • لَوۡ If
  • يَعۡلَمُ knew
  • ٱلَّذِينَ those who
  • كَفَرُواْ disbelieved
  • حِينَ (the) time
  • لَا (when) not
  • يَكُفُّونَ they will avert
  • عَن from
  • وُجُوهِهِمُ their faces
  • ٱلنَّارَ the Fire
  • وَلَا and not
  • عَن from
  • ظُهُورِهِمۡ their backs
  • وَلَا and not
  • هُمۡ they
  • يُنصَرُونَ will be helped!
If those who disbelieved but knew the time when they will not avert the Fire from their faces or from their backs and they will not be aided...1
Footnotes
1 - The completion of the sentence is understood to be "...they would not be asking in disbelief and ridicule to be shown the punishment."
[God] exalted be He, says: If those who disbelieved only knew of the time when they shall not [be able to] ward off, repel, the Hellfire from their faces, nor from their backs, nor shall they be helped, [nor] shall they be protected from it at the Resurrection (the response to the [conditional particle] law, 'if only', is [something along the lines of] 'they would not have said that').