إِنَّهُ عَلَىٰ رَجْعِهِ لَقَادِرٌ (Surely He is Powerful to bring him back...86:8) The word raj means 'to bring back'. The verse signifies that Allah Who has created him from a drop of seminal fluid is well able to bring him back to life after death a fortiori.
يَوْمَ تُبْلَى السَّرَائِرُ (on a day when all the secrets will be searched out.. 86:9). The word tubla literally means 'to test/examine' and sara'ir means 'secrets'. On the Day of Reckoning, the secrets will be tested and examined and laid bare. Man's beliefs, his thoughts, and his motives and intentions that were hidden in this life, and no one knew about them, will be revealed in the Hereafter.
Likewise, his deeds and actions that he had done secretly, and no one was aware of them in this world, all of them will be tested and scrutinised on the Plain of Gathering and will be laid bare. Said 'Abdullah Ibn ` Umar ؓ has said that on the Day of Judgment Allah will disclose the secrets of all human beings. The sign of every good or bad belief and action will be displayed on man's face, in the form of beauty or darkness or gloom [ depending on each individual's situation ]. [ Qurtubi ].