Quran 18:94 from Surah Al-Kahf on Divine Marvels.
قَالُواْ يَٰذَا ٱلۡقَرۡنَيۡنِ إِنَّ يَأۡجُوجَ وَمَأۡجُوجَ مُفۡسِدُونَ فِي ٱلۡأَرۡضِ فَهَلۡ نَجۡعَلُ لَكَ خَرۡجًا عَلَىٰٓ أَن تَجۡعَلَ بَيۡنَنَا وَبَيۡنَهُمۡ سَدّٗا
English translation: They said O Dhul-qarnain O Dhul-qarnain Indeed Yajuj and Majuj (are) corrupters in the land So may we make for you an expenditure [on] that you make between us and between them a barrier
Transliteration: qalu yadha al-qarnayni inna yajuja wamajuja muf'siduna fi al-ardi fahal naj'alu laka kharjan ala an taj'ala baynana wabaynahum saddan