﴿ فَهَلْ يَنظُرُونَ إِلَّا ٱلسَّاعَةَ أَن تَأْتِيَهُم بَغْتَةًۭ ۖ فَقَدْ جَآءَ أَشْرَاطُهَا ۚ فَأَنَّىٰ لَهُمْ إِذَا جَآءَتْهُمْ ذِكْرَىٰهُمْ ﴾

“Are, then, they [whose hearts are sealed] wait­ing for the Last Hour - [waiting] that it come upon them of a sudden? But it has already been foretold! And what will their remembrance [of their past sins] avail them, once it has come upon them?”

Please check ayah 47:19 for complete tafsir.