Quran 18:97 — Surah Al-Kahf, ayah 97

فَمَا ٱسۡطَٰعُوٓاْ أَن يَظۡهَرُوهُ وَمَا ٱسۡتَطَٰعُواْ لَهُۥ نَقۡبٗا

So Gog and Magog were unable to pass over it, nor were they able [to effect] in it any penetration

I tako oni nisu mogli ni da ga pređu niti su ga mogli prokopati.