Abu Musa relates that Allah’s Messenger ﷺsaid: “The case of the guidance and knowledge which Allah has endowed me with (and sent for your enlightenment) is like the rain which falls on land, part of which is good and fertile where dry grass turns green and considerable fresh vegetation is grown; and part of it is dry and it stores up the water and Allah makes it beneficial for human beings; they drink from it and get saturated and use it for cultivation. This rain water also reached a piece of land which is wide open plain, where the water was neither retained nor could it help produce grass. Similar is the case of those who understand the knowledge of religion which Allah has sent (to the people) through me, and benefited themselves from it; and also of those who learnt it and taught it to others. Another example is of those persons who neither raised their heads and learnt it nor accepted Allah’s guidance, sent to them through me.”
(Bukhari and Muslim)
The Seerah of Allah’s Messenger is one of the two basic sources of ultimate guidance. With the help of the simile of rain, the hadīth clarifies that as part of the land is fertile, similarly some people are wise enough to understand the knowledge of the religion. And, as some piece of land cannot retain the rain water, similarly there are people obstinate enough not to realise the wisdom inherent in the divine injunctions being unfolded to them by the Messenger of Allah.