(34) باب كَيْفَ يُقْبَضُ الْعِلْمُ
Narrated `Abdullah bin `Amr bin Al-`As:
I heard Allah's Messenger (ﷺ) saying, "Allah does not take away the knowledge, by taking it away from (the hearts of) the people, but takes it away by the death of the religious learned men till when none of the (religious learned men) remains, people will take as their leaders ignorant persons who when consulted will give their verdict without knowledge. So they will go astray and will lead the people astray."
Reference: Sahih al-Bukhari 100
In-book reference: Book 3, Hadith 42
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 1, Book 3, Hadith 100