The Prophet ﷺ said, "The guidance and knowledge with which Allah has sent me is like abundant rain that falls upon the earth. Some of the land is fertile, absorbing the water and producing vegetation and grass in plenty. Other parts are hard ground that holds the water, by which Allah benefits people, so they drink from it, give drink to others, and water their crops. Yet another portion is barren flat land that neither retains water nor grows any vegetation. That is the example of one who gains understanding of the religion of Allah and benefits from what Allah has sent me with, learning it and teaching it to others, and the example of one who pays it no heed and does not accept the guidance of Allah with which I was sent."
عن النبي ﷺ قال: إن مثل ما بعثني الله به عز وجل من الهدى والعلم كمثل غيث أصاب أرضا، فكانت منها طائفة طيبة قبلت الماء، فأنبتت منها الكلأ والعشب الكثير، وكان منها أجادب أمسكت الماء، فنفع الله بها الناس، فشربوا منها وسقوا ورعوا، وأصاب طائفة منها أخرى إنما هي قيعان: لا تمسك ماء، ولا تنبت كلا، فذلك مثل من فقه في دين الله، ونفعه بما بعثني الله به، فعلم وعلم، ومثل من لم يرفع بذلك رأسا، ولم يقبل هدى الله الذي أرسلت به.
Bukhari narrated it in the Book of Knowledge (79), and Muslim in the Book of Virtues (2282), through various routes from Abu Usama (Hammad bin Usama), from Burayd bin Abdullah, from Abu Burda, from Abu Musa, who related the hadith. The wording given is that of Muslim, and the wording of Bukhari is similar.