Allaah, Most High says,
“If we had sent down this Qur’an onto a mountain, you would have seen it humbled, crushing to pieces out of fear of Allaah…” [Al-Hashr:21]
Abu ‘Imran al-Jawni said, By Allaah, our Lord has directed such things to us in the Qur’an, which, were He to have directed to the mountains would have humbled and obliterated them.
Malik ibn Dinar, may Allaah have mercy on him, would recite this verse and say, ‘I swear to you, no servant believes in this Qur’an except that It causes his heart to burst.’ [Suyuti, al-Durr, vol. 14, pg.396]
Ibn Rajab al-Hanbali said regarding this verse, You, son of Adam, have a greater duty to yield to the remembrance of Allaah, and to what He has burdened you with of His Book and given you of His laws (than the mountains) since you will be judged and then find your final abode in Paradise or Hell.
[Book: The Humility in Prayer | Ibn Rajab al-Hanbali | Pages 34-36]