“And the good land – its vegetation emerges by permission of its Lord; but that which is bad – nothing emerges except sparsely, with difficulty. Thus do We diversify the signs for a people who are grateful.” (Surah Al-A’raf:58)

When rain falls on pure land that is not contaminated, vegetation grows by Allah’s Permission. This example is like that of a believer. When a believer receives revelation, he accepts it, learns it, benefits from it, grows with it, and benefits others around them. 

When rain falls on polluted, unclean land, nothing beneficial emerges from it. This is similar to the disbeliever. When revelation comes to a disbeliever, they are not affected by it. They are heedless and produce no benefit. 

The Messenger of Allah (peace and blessings of Allah be upon him) said, 

“The parable of the guidance and knowledge with which Allah has sent me is that of an abundant rain falling on a land, some of which was fertile soil that absorbed rain water and brought forth vegetation and grass in abundance. And another portion of it was hard and held the rain water; and Allah benefited the people with it, they utilized it for drinking, making their animals drink from it, and for irrigation of the land for cultivation. And a portion of it was barren which could neither hold the water nor bring forth vegetation. The first is the example of the person who comprehends Allah’s religion and gets benefit which Allah sent me with, by learning and teaching others. The last example is that of a person who does not care for it and does not accept the guidance Allah sent me with.” (Al Bukhari)