(Surah Qaf 50...
In these verses they are interpreted to be the hardships of death. The hardships of death are not physical pains and discomfort; on the contrary it is spiritual and internal and it is much more severe than physical tortures. Physical pains are felt through senses and they reach the soul from this channel, but spiritual and internal chastisements scorch the being.
Hardships of death can be from various aspects: Attachment to what he has gathered in his life: Like the house, property, wealth, children and other worldly things. Man struggled all his life to obtain them and committed lawful and unlawful acts in their pursuit with the hope that they would give him some advantage at the end of his life. Their love had taken a deep root in his being that it is very difficult for him to ignore them now.
At the time of death, he sees that he would be compelled to leave every worldly thing to which he was attached and move to the everlasting world of the hereafter empty-handed. Seeing his past deeds: Throughout his life man continues to commit numerous small and big sins and after sometime forgets most of them in such a way that as if he had never committed them. He does not even recall them in order to repent for them.
While the fact is that all his words, acts and morals are recorded in the scroll of his deeds and these same deeds have earned for him Hell and the chastisement of Hell. At the time of death, the curtain will be removed from his eyes and he will see each act committed by him during his lifespan and the recompense of the same. And how severe it would be for one to see all one has committed in his lifespan in an instant?