Sura 3 Ali 'Imran (Family of Imran), ayah 106

1. يَوْمَ تَبْيَضُّ وُجُوهٌ وَتَسْوَدُّ وُجُوهٌ ۚ فَأَمَّا الَّذِينَ اسْوَدَّتْ وُجُوهُهُمْ أَكَفَرْتُمْ بَعْدَ إِيمَانِكُمْ فَذُوقُوا الْعَذَابَ بِمَا كُنْتُمْ تَكْفُرُونَ

   On the Day (some) faces will turn white and (some) faces will turn black. As for those whose faces turn black, (to them it will be said), "Did you disbelieve after your belief? Then taste the punishment for what you used to reject."

   3:106

Translation: Saheeh International