The Prophet ﷺ said, "The guidance and knowledge with which Allah has sent me is like abundant rain falling on the earth. Some of the ground was fertile and absorbed the water, bringing forth grass and plants in abundance. Other ground was hard and held the water, and Allah benefited people through it so they drank from it, gave drink to others, and watered their crops. Yet another portion of it was barren flatland that neither retained water nor produced any vegetation. This is the example of one who gains understanding in 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 no attention to it and does not accept the guidance of Allah with which I have been sent."
ى، 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 الكلا، 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 كلأ، 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, and he related the hadith. The wording given is Muslim's, and Bukhari's wording is similar.His saying, "qian," is with a kasra on the qaf, the plural of qaa, which is flat, smooth ground on which nothing grows.