Tafseer Ibn Kathir of AZ ZUKHRUF [65]

فَاخْتَلَفَ الْأَحْزَابُ مِن بَيْنِهِمْ فَوَيْلٌ لِّلَّذِينَ ظَلَمُوا مِنْ عَذَابِ يَوْمٍ أَلِيمٍ

But the denominations from among them differed [and separated], so woe to those who have wronged from the punishment of a painful Day.