يَوْمَ تَبْيَضُّ وُجُوهٌ وَتَسْوَدُّ وُجُوهٌ ۚ فَأَمَّا ٱلَّذِينَ ٱسْوَدَّتْ وُجُوهُهُمْ أَكَفَرْتُم بَعْدَ إِيمَـٰنِكُمْ فَذُوقُوا۟ ٱلْعَذَابَ بِمَا كُنتُمْ تَكْفُرُونَ
Yawma tabyaddu wujoohunw wa taswaddu wujooh; faammal lazeenas waddat wujoohum akafartum ba'da eemaanikum fazooqul 'azaaba bimaa kuntum takfuroon
pada hari yang di waktu itu ada muka yang putih berseri, dan ada pula muka yang hitam muram. Adapun orang-orang yang hitam muram mukanya (kepada mereka dikatakan), "Kenapa kamu kafir sesudah kamu beriman? Karena itu, rasakanlah azab disebabkan kekafiranmu itu".
On the day when some faces will be bright and some faces will be dark — as for those whose faces are darkened: did you deny after your belief? Then taste the punishment for the denial you held to.
Arabic already used a whitened face for vindication and a blackened one for disgrace, the idiom behind the man in Surah An-Nahl whose face darkens at news of a daughter, so the image carries public standing before it carries colour. Whether that day makes the idiom literal or keeps it figurative is a question the commentaries leave open. The verse also lands directly after the warning against splitting into factions.