﴿ وَأَنذِرْهُمْ يَوْمَ ٱلْحَسْرَةِ إِذْ قُضِىَ ٱلْأَمْرُ وَهُمْ فِى غَفْلَةٍۢ وَهُمْ لَا يُؤْمِنُونَ ﴾

“hence, warn them of [the coming of] the Day of Regrets, when everything will have been decided-for as yet they are heedless, and they do not believe [in it].”

(And warn them) O Muhammad (of the Day of anguish) of the Day of regret (when the case hath been decided) when the reckoning is over and the people of Paradise enter Paradise and the people of hell enter hell and Death is slain. (Now they are in a state of carelessness) in a state of ignorance and blindness concerning it, (and they believe not) in Muhammad (pbuh) in the Qur'an or in resurrection after death.