سورة Al-Kahf 18:97

فَمَا ٱسْطَـٰعُوٓا۟ أَن يَظْهَرُوهُ وَمَا ٱسْتَطَـٰعُوا۟ لَهُۥ نَقْبًۭا ٩٧

And so the enemies could neither scale nor tunnel through it