Surah 25. Al-Furqan, Ayah 49

The whole cycle of water,-sea, clouds, rain or hail or snow, rivers, and sea again,-is a remarkable illustration of the processes of nature making Allah's providence visible to us. The salts of the sea sanitate and purify all the filth that pours into it. Water action, in the form of rain, frost, glaciers, rivers, lakes, etc., is responsible for the building up and configuration of the crust of the earth, and is the chief agent in physical geography. A parched desert quickly comes to life under the action of water. All drinking water, whether derived from rivers, canals, lakes, reservoirs, springs, wells, or water-works of any kind, are ultimately traceable to rain. The connection of life with water is intimate. The physical basis of life itself, protoplasm, is in great part water; see xxv. 54 below.