The diwan was a political council and state bureaucracy under Caliph Umar, responsible for the administrative order in the Islamic Caliphate.
The diwan referred to by the student was a political council and an administrative body established during the reign of the second Caliph, Umar, who succeeded Abu Bakr in 634. The diwan was a state bureaucracy with a treasury and separate departments responsible for tax collection, public safety, and the exercise of sharia law in the expanding Islamic Caliphate. As part of the Caliphate administration, the diwan played a crucial role in organizing and managing the vast territories under Muslim rule.