A person considered a religious successor to the Islamic prophet Muhammad (Muhammad ibn ʿAbdullāh) and a leader of the entire Muslim community would have used what financial institution?
Bayt al-mal Bayt al-mal (بيت المال ) is an Arabic term that is translated as "House of money" or "House of Wealth." Historically, it was a financial institution responsible for the administration of taxes in Islamic states, particularly in the early Islamic Caliphate. It served as a royal treasury for the caliphs and sultans, managing personal finances and government expenditures. Further, it administered distributions of zakat revenues for public works. Modern Islamic economists deem the institutional framework appropriate for contemporary Islamic societies.
Al-Qa'im bi-Amr Allah Abu'l-Qasim Muhammad ibn al-Mahdi (Arabic: أبو القاسم محمد بن المهدي القائم بأمر الله‎ ‎ ; April 893 – 17 May 946), better known by his regnal name al-Qa'im bi-Amr Allah or bi-Amri 'llah (القائم بأمر الله , "He who carries out God's orders"), was the second caliph of the Fatimid Caliphate in Ifriqiya and ruled from 934 to 946. He is the 12th Imam according to the Isma'ili faith.