Tafsir of Al-Fajr 89:21

{Nay!} A rebuke to them regarding that, and a denial of their actions. Then, the threat is brought forth, and their regret for what they neglected is mentioned at a time when regret is of no avail.

{And on that day} is a substitute for {When the earth is crushed}, and the governing agent for the accusative case in both is {he will remember}.

{Crushed, crushed} means crushed after crushed, like the saying: "I counted it door by door," meaning: the crushing is repeated upon it until it becomes scattered dust.

If you ask: What is the meaning of attributing "coming" to Allah, when movement and transition are only permissible for one who is in a direction? I say: It is a metaphor for the manifestation of the signs of His omnipotence and the clarity of the traces of His subjugation and authority. His state in that is likened to the state of a king who, when he attends in person, there appears through his presence such traces of awe and governance that would not appear through the presence of all his armies, ministers, and elite attendants in their entirety.

{In rows, in rows} The angels of every heaven will descend and stand in rows, one after another, surrounding the Jinn and mankind.

{And on that day, Hell is brought} is like His saying: {And Hell-fire will be laid open} (An-Nazi'at: 36). It is narrated that when this was revealed, the face of the Messenger of Allah (ﷺ) changed, and it was recognized in his face, which distressed his companions. They informed Ali (may Allah be pleased with him), so he came, embraced him from behind, kissed him between his shoulders, and said: "O Prophet of Allah, may my father and mother be sacrificed for you, what has happened today? What has changed you?" He recited the verse to him. Ali said: "How will it be brought?" He replied: "Seventy thousand angels will bring it, leading it with seventy thousand reins. It will bolt in such a way that, if it were left alone, it would burn everyone at the Gathering."

{He will remember} means he will remember what he neglected, or he will take heed.

{But how will the remembrance avail him?} From where will the benefit of remembrance come to him? It is necessary to assume the omission of a genitive noun (mudaf), otherwise, there would be a contradiction between "the day he remembers" and "how will the remembrance avail him."

{I had sent forth for my life} This life, which is the life of the Hereafter, or the time of my life in the world, like your saying: "I came to him ten nights after the beginning of Rajab." This is the clearest evidence that the choice was in their hands and dependent on their intentions and will, and that they were not veiled from acts of obedience or compelled to commit sins, as is the doctrine of the people of desires and innovations; otherwise, what would be the meaning of the regret?

{He will punish... he will bind} (with the fatha on the dhal and tha): This is the recitation of the Messenger of Allah (ﷺ). Abu 'Amr narrated that he returned to this recitation at the end of his life. The pronoun refers to the "man" previously described. It is said: It is Ubayy ibn Khalaf, meaning: No one is punished like his punishment, and no one is bound in chains and shackles like his binding, due to his extremity in disbelief and stubbornness. Or, no one bears the punishment of man, like His saying: {And no bearer of burdens shall bear the burden of another} (Al-Isra: 15).

{He will punish... he will bind} (with the kasra on the dhal and tha): The pronoun refers to Allah the Exalted, meaning: No one shall take charge of Allah’s punishment, because the command belongs to Allah alone on that day. Or, it refers to man, meaning: None of the guards (Zabaniyah) will punish like they punish him.

{O soul at peace! Return to your Lord, well-pleased and well-pleasing! Enter among My servants!}