1. The ruling of doing an act whilst not knowing its ruling.
The scholars have determined that it is obligatory upon a person to know the ruling of every action before they do it in order to be sure that it is not prohibited. A consensus has been mentioned about the prohibition of doing an action whilst not knowing its ruling.
It was reported that Umar bin al Khattab (ra) would not permit anyone who did not know the rulings of buying and selling to trade in the market. He used to say: “No one should trade in our markets unless he has learnt the fiqh of the religion (tafaqqaha fid-deen).”
The scholars have also mentioned that if a particular country did not have a mufti and it was not possible for the layman to consult mujtahideen; it becomes obligatory upon him to make hijrah and it is not permissible for him to remain in such a country.
However, in reality this issue does not apply to today’s circumstances due to the widespread availability of modern means of communication.