Tafsir of Al-Kahf 18:99

{And We will leave some of them that day...}

{And We will leave}: We will cause {some of them}—some of the creation—{to surge over others}: meaning they will be in turmoil and intermingled, both their humans and their jinn, in a state of confusion.

It is also possible that the pronoun refers to Gog and Magog, and that they will surge when they emerge from behind the barrier, crowding into the lands. It is narrated that they will come to the sea and drink its water, eat its creatures, then eat the trees, and consume anyone they capture among the people who have not fortified themselves against them. However, they will not be able to enter Makkah, Madinah, or Bayt al-Maqdis. Then, Allah will send naghaf (larvae) into the backs of their necks, which will enter their ears, causing them to die.

{And We will present Hell that day to the disbelievers, in full view—those whose eyes were under a cover from My remembrance, and they were not able to hear.}