Surah Al-Kahf 18:94

قَالُوا۟ يَـٰذَا ٱلْقَرْنَيْنِ إِنَّ يَأْجُوجَ وَمَأْجُوجَ مُفْسِدُونَ فِى ٱلْأَرْضِ فَهَلْ نَجْعَلُ لَكَ خَرْجًا عَلَىٰٓ أَن تَجْعَلَ بَيْنَنَا وَبَيْنَهُمْ سَدًّا

They said, "O Dhul-Qarnayn, indeed Gog and Magog are [great] corrupters in the land. So may we assign for you an expenditure that you might make between us and them a barrier?"

Translation: Saheeh International

Tafsir

They said ‘O Dhū’l-Qarnayn truly Gog and Magog read Ya’jūj wa-Ma’jūj or Yājūj wa-Mājūj these two are non-Arabic names of two tribes and are therefore indeclinable are causing corruption in the land plundering and oppressing us when they come forth to attack us. …

Excerpt from Tafsir al-Jalalayn, commentary on 18:94, via Quran.com. The reader has the full commentary and 9 more tafsirs.