إِنَّ في ذٰلِكَ لَآيَةً لِمَن خافَ عَذابَ الآخِرَةِ ۚ ذٰلِكَ يَومٌ مَجموعٌ لَهُ النّاسُ وَذٰلِكَ يَومٌ مَشهودٌ

This is a warning for those who fear the punishment of the Hereafter. That’s a Day for which the people will be gathered, and that’s a Day witnessed.