And [when] the true promise [i.e., the resurrection] has approached; then suddenly the eyes of those who disbelieved will be staring [in horror, while they say], "O woe to us; we had been unmindful of this; rather, we were wrongdoers."
Those who have been destroyed, will never return to this World.
وَحَرَامٌ عَلَى قَرْيَةٍ
(And a ban is laid on every town) Ibn `Abbas said, "it is enforced", i.e., it has been decreed that the people of each township that has been destroyed will never return to this world before the Day of Resurrection, as is reported clearly through other narrations from Ibn `Abbas, Abu Ja`far Al-Baqir, Qatadah and others.
Ya'juj and Ma'juj
حَتَّى إِذَا فُتِحَتْ يَأْجُوجُ وَمَأْجُوجُ
(Until, when Ya`juj and Ma`juj are let loose,) We have already mentioned that they are from the progeny of Adam, upon him be peace; they are also descents of Nuh through his son Yafith (Japheth), who was the father of the Turks, Turk referring to the group of them who were left behind the barrier which was built by Dhul-Qarnayn. Allah says:
حَتَّىٰ إِذَا فُتِحَتْ يَأْجُوجُ وَمَأْجُوجُ وَهُم مِّن كُلِّ حَدَبٍ يَنسِلُونَ (Until when the Ya'juj and Ma'juj (Gog and Magog) are released, while they run down from every height - 21:96.) In the previous verse it was said that those who died in a state of unbelief will never return to this world. The phrase "until the Ya'juj and Ma'juj appear", really means that such people will never return, because the appearance of Ya'juj and Ma'juj will be a sign of near approach of the Dooms Day.
It is reported in Sahih of Muslim through Sayyidna Hudhaifah ؓ that he and some other Sahabah ؓ ، were in the midst of a discussion when the Holy Prophet ﷺ came to them and enquired as to what were they deliberating. They replied that they were discussing about the Qiyamah (Dooms Day). Thereupon he said that Qiyamah will occur only after ten signs have become manifest, and the appearance of Ya'juj and Ma'juj will be one of them.
When the Truth appears with clear arguments, a man is compelled to recognise it by the compulsion of his very nature. Now, those who accept the Truth after recognising it, remain in consonance with their nature. On the other hand, those who give importance to material things and, therefore, do not accept the Truth, are as if ignoring their nature—virtually casting a veil over it. Denial of Truth is always at the cost of shutting one’s senses. The fate of those who run this risk is that their entry into Islam becomes absolutely impossible: they are no longer receptive to the truth. Those who fail to recognise the Truth, though presented in rational arguments, will recognise it only when the Day of Judgement tears the veil away from their eyes. But, recognition at that stage will be of no avail, because it will be time not for acceptance itself, but for reaping the benefit of an earlier acceptance of the Truth.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.