18:97
فَمَا ٱسْطَـٰعُوٓا۟ أَن يَظْهَرُوهُ وَمَا ٱسْتَطَـٰعُوا۟ لَهُۥ نَقْبًا
famā is'ṭāʿū an yaẓharūhu wamā is'taṭāʿū lahu naqban
Their enemies could not scale the barrier, nor could they pierce it,
So they [Ya’jûj and Ma’jûj (Gog and Magog)] could not scale it or dig through it.