The example of guidance and knowledge

Narrated Abu Musa: The Prophet said, "The example of guidance
and knowledge with which Allah has sent me is like abundant
rain falling on the earth, 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 and 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 (then that land gave no benefits).
The first is the example of the person who comprehends Allah's
religion and gets benefit (from the knowledge) which Allah has
revealed through me (the Prophets and learns and then teaches
others. The last example is that of a person who does not care
for it and does not take Allah's guidance revealed through me
(He is like that barren land.)"

[Sahih Al-Bukhari, Volume 1 , Book 3, Hatheeth no 79]