And when he began with the signs of the heavens, because they are more famous and more general in terms of fear and terror, and he mentioned two of them, which are the most famous and the most beneficial among them, he followed them with the signs of the earth. He said, repeating for the context to give more attention to the terror: "And when the mountains..." meaning those which are in the lower world like the stars in the upper world, and they are the hardest of what is in the earth. This indicates the greatness of the power by the construction for the acted upon, so he said: "They will be set in motion..." meaning the occurrence of their being set in motion towards the face of the earth, so they became as if they were clouds in movement and dust in scattering, so that the earth may become a flat expanse with no crookedness in it, because that day does not accept crookedness in anything of the things in any way.