The system of Islamic insurance is based on the principle of mutual understanding and gift giveaway donation where the risk is shared collectively by the group voluntarily.
This is a pact among a group of members who agree to jointly guarantee among themselves against loss or damage to any of them as defined in the pact. Takaful is an Arabic word which means guaranteeing each other.
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 Arab states, particularly in the early Islamic Caliphate around 600 AD. It served as a royal treasury for the caliphs and sultans, managing personal finances and government expenditures. Further, it administered distributions of zakat (compulsary charity) revenues for public works.
Source : Wiki