The wonderful system of rains on the earth, the resulting growth of greenery and the subsequent preparations for harvesting, have countless meaningful lessons in them. But, these lessons are available only to those who devote themselves to deep thought. On the one hand, God has created the external world in a way that everything in it has become a sign of great realities, and, on the other, He has endowed man with the ability to read these signs and understand them. Those who keep their natural capabilities alive and, by utilising them, give deep consideration to the things of the world, will have their minds filled with the deep realisation (ma‘rifah) of God. Whereas those who do not keep these capabilities alive, will be unable to learn anything, even though surrounded by countless lessons. They will not be able to see, even after seeing, and will not be able to hear, even after hearing.