Al-Kahf · 18:98

98. Dhu’l-Qarnayn said: “This barrier is a mercy from my Lord. It will come between Gog and Magog and causing corruption on earth, and it will stop them from it. Then when the time which Allah has appointed for their release comes before the Final Hour, He will level it to the ground. And the promise of Allah to level it to the ground and to release Gog and Magog is established and will not be broken”.