Once whilst Ali (radiyallahu anhu) was seated on the mimbar, someone asked him a question. Without any hesitation, he calmly replied: “I don’t know.” The man commented: “How can you ever say: “I don’t know” when you have assumed this exalted position of sitting on the mimbar?” To this Ali (radiyallahu anhu) replied: “I’ve ascended this mimbar based on what I know. Had I ascended any place based on what I don’t know then undoubtedly I would have reached the sky!” (Mirqaat vol.1 pg. 528)
Lesson: Besides Allah Ta’ala nobody knows everything.
Then there are those who have more knowledge than others. In every field, there are experts and there are laymen. Laymen must NEVER take a chance. They must always refer to the experts, whether it be a medical problem, a financial issue or any other aspect.
Most importantly, those without sound knowledge of Deen must NEVER take a chance with trying to extract laws of deen from the Quraan and Sunnah.
One must ALWAYS refer to the experts – those who have acquired the detailed knowledge of the Quraan and Sunnah from experts – via an unbroken chain leading all the way up to Rasulullah (sallallahu alaihi wasallam). Allah Ta’ala clearly commands “Ask those of knowledge if you do not know.”