"Indeed, I fear for you the like of the day of the confederates [Al-Ahzab]," meaning: the like of the punishment of the past nations. Then he informed them about the day of the confederates, saying:
﴿إِنِّي أَخَافُ عَلَيْكُمْ مِثْلَ يَوْمِ الْأَحْزَاب﴾ يَعْنِي: مثل عَذَاب الْأُمَم الخالية , ثمَّ أخبر عَن يَوْم الْأَحْزَاب) ﴿فَقَالَ
