Hell will be displayed before the Disbelievers on the Day of Resurrection
Allah tells us what He will do to the disbelievers on the Day of Resurrection. He will show Hell to them, meaning He will bring it forth for them to see its punishment and torment before they enter it. This will intensify their distress and grief. In Sahih Muslim it is recorded that Ibn Mas`ud said, "The Messenger of Allah ﷺ said,
(Hell will be brought forth on the Day of Resurrection, pulled by means of seventy thousand reins, each of which will be held by seventy thousand angels.) Then Allah says of them:
As for the pronoun of the word: بَعْضَهُمْ (ba` dahum) in بَعْضَهُمْ يَوْمَئِذٍ يَمُوجُ فِي بَعْضٍ (And on that day, We will leave them [ Ya’ juj and Ma'juj ] surging over one another - 99), it is obvious that it reverts back to Ya'juj Ma juj. Then, as for their condition described therein - 'surging over one another' - it is also obvious that this will be their state when the passage lies open for them and they will be hastening their way from the hilly heights down to the ground. Commentators have suggested other probabilities as well.
The pronoun in: فَجَمَعْنَاهُمْ (fajama'nahum: Then We shall gather them together - 99) is reverting back to the creation at large, human beings and the Jinn. The sense is that the entire creation of human beings and the Jinn who have been obligated with the percepts of the Shari` ah (mukallaf) shall be gathered together on the plains of Resurrection (al-Hashr).
Tazkirul Quran
Maulana Wahiduddin Khan
At the onset of Doomsday, the present world will no longer be the same. It appears that the present boundaries between mountains and rivers will disappear and huge crowds of human beings will lap against one other like the waves of the ocean. Today, Hell is being shown to people through their ‘mental eyes’, but they fail to perceive it. On Doomsday, Hell will be shown to people through their physical eyes. At that time, everybody will see it. But this seeing will be of no avail except to one who had removed the veil from his eyes, having learned a lesson from divine advice in his pre-death life. The removal of veil on the Day of judgement, will be solely for the purpose of sending the arrogant and insolent disbelievers to their destined end in hell.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.