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 sit-ting 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 un-doubtedly 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.”