The Family of Imran
يَوْمَ تَبْيَضُّ وُجُوهٌ وَتَسْوَدُّ وُجُوهٌ ۚ فَأَمَّا ٱلَّذِينَ ٱسْوَدَّتْ وُجُوهُهُمْ أَكَفَرْتُم بَعْدَ إِيمَـٰنِكُمْ فَذُوقُوا۟ ٱلْعَذَابَ بِمَا كُنتُمْ 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."
Nearby ayahs help place verse 3:106 in sequence and meaning.
وَلْتَكُن مِّنكُمْ أُمَّةٌ يَدْعُونَ إِلَى ٱلْخَيْرِ وَيَأْمُرُونَ بِٱلْمَعْرُوفِ وَيَنْهَوْنَ عَنِ ٱلْمُنكَرِ ۚ وَأُو۟لَـٰٓئِكَ هُمُ ٱلْمُفْلِحُونَ
And let there be [arising] from you a nation inviting to [all that is] good, enjoining what is right and forbidding what is wrong, and those will be the successful.
وَلَا تَكُونُوا۟ كَٱلَّذِينَ تَفَرَّقُوا۟ وَٱخْتَلَفُوا۟ مِنۢ بَعْدِ مَا جَآءَهُمُ ٱلْبَيِّنَـٰتُ ۚ وَأُو۟لَـٰٓئِكَ لَهُمْ عَذَابٌ عَظِيمٌ
And do not be like the ones who became divided and differed after the clear proofs had come to them. And those will have a great punishment.
وَأَمَّا ٱلَّذِينَ ٱبْيَضَّتْ وُجُوهُهُمْ فَفِى رَحْمَةِ ٱللَّهِ هُمْ فِيهَا خَـٰلِدُونَ
But as for those whose faces will turn white, [they will be] within the mercy of Allah. They will abide therein eternally.
تِلْكَ ءَايَـٰتُ ٱللَّهِ نَتْلُوهَا عَلَيْكَ بِٱلْحَقِّ ۗ وَمَا ٱللَّهُ يُرِيدُ ظُلْمًا لِّلْعَـٰلَمِينَ
These are the verses of Allah. We recite them to you, [O Muhammad], in truth; and Allah wants no injustice to the worlds.