And We have made the night and the day two signs, then We have made the sign of the night to pass away and We have made the sign of the day manifest, so that you may seek grace from your Lord, and that you might know the numbering of years and the reckoning; and We have explained everything with distinctness.

Do you not see that Allah drives along the clouds, then gathers them together, then piles them up, so that you see the rain coming forth from their midst? And He sends down of the clouds that are (like) mountains wherein is hail, afflicting therewith whom He pleases and turning it away from whom He pleases; the flash of His lightning almost takes away the sight.