What are the financial authorities of the ruler in Islam?

The ruler must fulfill trusts of two types: First, leadership positions (wilayat), so he should appoint the most suitable for the Muslims. Second, wealth, so he should fear God concerning it. He is not permitted to distribute it according to his whims, for he is a trustee, a deputy, and an agent, not an owner, as the Prophet, peace and blessings be upon him, said: "By Allah, I do not give to anyone nor do I withhold from anyone; I am but a distributor, placing [wealth] where I have been commanded."