The Messenger of Allah (sal Allahu alaihi wa sallam) said, “An example of the guidance and knowledge with which Allah has sent me is that of a rain that falls on different kinds of lands. One land is good; it accepts water and produces vegetation and grass in plenty. Another kind of land is dry with a solid bed that preserves the rain water so that people can drink and irrigate from it. The third kind of land is porous that can neither retain water nor produce vegetation. This is the example of those who acquire knowledge of the religion and benefit from that which Allah sent me with, and of those who do not take heed and insist on rejecting Allah’s Guidance.” [Bukhari]
The Messenger (sal Allahu alaihi wa sallam) likens the knowledge of Islam to rain, because both are causes of life. Rain is the cause of life for the body, while knowledge is the cause of life for the heart. Thus, just as there are three kinds of lands or soil, there are also three kinds of hearts:
1) The first is fertile land which accepts water and is ready to produce vegetation. When rain falls on it, it absorbs the water eagerly, giving rise to all sorts of pleasant vegetation. This is the example of a healthy, pure, and intelligent heart, which embraces knowledge, is guided by its intelligent nature, and thus blossoms wisdom and faith. It is eager to take knowledge, and ready to bear fruits. It is like a rich businessman who has experience and knowledge, which enables him to invest his wealth in that which brings the best profit.
2) The second kind of land is hard. It can hold water as a reservoir does and can be used to drink or irrigate from. This is the example of the heart that preserves knowledge so as to convey it accurately to others. But this person cannot extrapolate or derive conclusions from the knowledge himself. He is like a rich man who does not possess the ability to invest his wealth and increase it, but who knows how to preserve it.
3) The third kind of land is barren. It is incapable of producing vegetation or even holding water. No matter how much rain falls on it, it does not benefit by it. This is the example of the heart that does not accept any knowledge or wisdom at all. This is like a poor man who neither possesses wealth nor can he increase or preserve it.
The first of the above three examples applies to a learned man who teaches knowledge, and who calls people to Allah (subhana wa ta’ala) with clear guidance; such are the inheritors of the Prophets. The second applies to one who preserves the knowledge and transmits what he hears precisely; he carries to other people precious goods that they can use for trade and investment. The third applies to one who neither accepts Allah’s Guidance nor benefits from it.