(… يُنَبَّأُ الْإِنسَانُ يَوْمَئِذٍ) (Man will be informed that Day …): On that Day, when the moon and the sun will be brought together and wrapped in darkness, the human being will be informed of what he sent ahead and kept back. This is similar to Allah’s saying:

 وَكُلَّ إِنسَانٍ أَلْزَمْنَاهُ طَائِرَهُ فِي عُنُقِهِ ۖ وَنُخْرِجُ لَهُ يَوْمَ الْقِيَامَةِ كِتَابًا يَلْقَاهُ مَنشُورًا (13) اقْرَأْ كِتَابَكَ كَفَىٰ بِنَفْسِكَ الْيَوْمَ عَلَيْكَ حَسِيبًا

(And [for] every person We have imposed his fate upon his neck, and We will produce for him on the Day of Resurrection a record which he will encounter spread open (13) [It will be said], “Read your record. Sufficient is yourself against you this Day as accountant.”) (Al-Israa: 13-14)

(  بِمَا قَدَّمَ وَأَخَّرَ… ) (…of what he sent ahead and kept back): The human beings will be informed of what they have done of good and bad deeds during their lifetime, as well as, their good or bad practices that the people followed after their death. So, Allah (swt) will inform them of the deeds they have done and also about what they delayed and have not done.