Riyad us-Salihin Hadith 1378

The Messenger of Allah (ﷺ) said, "The guidance and knowledge with which Allah has sent me are like abundant rain which fell on a land. A fertile part of it absorbed the water and brought forth profuse herbage and pasture; and solid ground patches which retained the water by which Allah has benefited people, who drank from it, irrigated their crops and sowed their seeds; and another sandy plane which could neither retain the water nor produce herbage. Such is the similitude of the person who becomes well-versed in the religion of Allah and receives benefit from the Message entrusted to me by Allah, so he himself has learned and taught it to others; such is also the similitude of the person who has stubbornly and ignorantly rejected Allah's Guidance with which I have been sent." [Al-Bukhari and Muslim]