Tafsir of Az-Zalzala 99:6

"That Day"—meaning the day when what was mentioned occurs. It acts as an adverbial phrase for His saying, "the people will depart"—meaning they will emerge from their graves, after having been buried in them, toward the place of reckoning, "scattered"—divided according to their stations: white-faced and secure, and black-faced and fearful; some riding and some walking; some bound in chains and some unbound. It is reported from some of the predecessors that they are divided into the fortunate and the most fortunate, and the wretched and the most wretched. It is also said: into believers and disbelievers. From Ibn Abbas: the people of faith are together on one side, and the people of every [other] group are together on their own side. It has been permitted that the meaning is each one individually, having no helper or supporter, like His saying: "And you have come to Us alone." It is also said: scattered according to [their] regions, "that they may be shown their deeds"—meaning that they may behold the recompense for their deeds, whether good or evil. Thus, the vision is visual, and the statement is based on the omission of a genitive (i.e., 'recompense of'), or it is a metaphor, where 'deeds' refers to the recompense resulting from them. Some have estimated it to mean 'their records' or 'their scrolls'. Others have said there is no need for such interpretation, and that deeds are embodied as light or darkness; in fact, it is possible to see them despite their being accidents (non-substances), though this is as you see [i.e., problematic]. Others say the meaning is that they may know their deeds and be informed of them in detail at the reckoning, thus not requiring what was previously mentioned. Al-Naqqash said: Departure (sudur) is the opposite of arrival (wurud); they arrive at the Gathering place and depart from it scattered—one group to Paradise and one group to the Fire, that they may see the recompense of their deeds consisting of Paradise and Hellfire. This is not strong. Regardless, His saying, "that they may be shown" is connected to "they will depart." It is also said that it is connected to "that your Lord has inspired it," with what lies between them being a parenthetical clause. Al-Hasan, al-A’raj, Qatada, Hammad bin Salama, al-Zuhri, Abu Haywah, ‘Isa, and Nafi’ (in one narration) read li-yaraw (to see) with a fathah on the ya.