وَأَنذِرْهُمْ يَوْمَ الْحَسْرَةِ إِذْ قُضِيَ الْأَمْرُ وَهُمْ فِي غَفْلَةٍ وَهُمْ لَا يُؤْمِنُونَ

Warn them of the Day of Regret, when the matter will be decided, while they are [yet] heedless and do not have faith.