﴿ يَوْمَ تَرْجُفُ ٱلْأَرْضُ وَٱلْجِبَالُ وَكَانَتِ ٱلْجِبَالُ كَثِيبًۭا مَّهِيلًا ﴾

“on the Day when the earth and the mountains will be convulsed and the mountains will [crumble and] become like a sand-dune on the move!”

Then Allah explained when this will take place, saying: (On the day when the earth and the hills rock) on the day when the earth and the mountains will quake, (and the hills become a heap of running sand.