(Al-Vaqia) 56 : 70
لَوْ نَشَاءُ جَعَلْنَاهُ أُجَاجًا فَلَوْلَا تَشْكُرُونَ
If We had wished, We would have made it bitter salty, then why don’t you become grateful?
Even though the salty water from the sea is evaporated and is formed in to clouds, and it condenses and comes to the earth as rain water, it is the Almighty Allah who transforms it as suitable for drinking and watering facilities. So it is asked through this verse that even though Allah does all these facilities for the mankind, why they don’t become grateful. See explanation 36: 35-36.