Have you not seen that Allah has subjected to you whatever is in the earth and (also) the vessels that sail in the sea (and river) by His Command (i.e. Law) and He withholds the heavens (spatial spheres and atmospheric fields) from falling on to the earth (under a cosmic system)? But (when He wills, they will collide) by His Command. Surely Allah is Most Compassionate, Most Merciful to mankind.