(… وَلَوْ تَرَىٰ ) (If you could but see …): Allah (swt) is addressing the Prophet (saws).
(… إِذْ وُقِفُوا عَلَىٰ رَبِّهِمْ ۚ… ) (…when they will be made to stand before their Lord.…): When they will stand in this Place of Standing.
(… قَالَ أَلَيْسَ هَٰذَا بِالْحَقِّ ۚ… ) (…He will say, “Is this not the truth?”…): This was what you used to deny when you were in the world. You believed that you would not be resurrected, nor stand in this place. They will all attain certain knowledge and see the reality of the heaven and hell, like the saying of Ali (may Allah be pleased with him): “By Allah, if the veil were to be lifted from me and I could see the real Paradise and Hellfire, this would not increase my faith, even a bit.” This is because, he had fully believed in Allah (swt) and the Prophet (saws). So, since the claim that this worldly life is the end of it all does not intellectually stand, it is only fitting that we believe that there is a Day of Recompense which will keep the human being’s movements in life in check. It will also ensure that he does not stray from the moral and ethical rules and remind him that there will be a day when his actions will be laid out and that every big, small or even the minutest deed will be counted. On this day too, he will be subject to the mercy of Allah (swt) and to His punishment, because of the sins he had committed.