Now, can a man possessed of any common sense claim that this wise property in water has come about by itself under some blind and deaf law of nature? This characteristic by virtue of which sweet, pure water is distilled from saltish seas and falls as rain, and then serves as a source of water-supply and irrigation in the form of rivers, canals, springs and wells, provides a clear proof of the fact that the Provider has endowed water with this property thoughtfully and deliberately for the purpose that it may become a means of sustenance for His creatures. Then, neither could man have survived by drinking that water, nor could it help grow any vegetation. In this case the vapors that arise from the oceans would have contained the sea salt, which would have made the soil saline and uncultivable wherever it rained.
Had it not possessed this property the dissolved substances also would have evaporated along with the water vapors. Among the wonderful properties that Allah has created in water, one property also is that no matter what different substances are dissolved in water, when it changes into vapor under the effect of heat, it leaves behind all adulterations and evaporates only with its original and actual component elements. In this sentence an important manifestation of Allah’s power and wisdom has been pointed out. (56:70) If We had so pleased, We could have made it bitter.