Almsgiving (Zakat)
The fourth Pillar of Islam is to give alms to the poor. Muslims are supposed to donate a fixed amount of their property to charity every year.

Many pious individuals, from the mightiest rulers to modest merchants, give money to help out the less-fortunate by establishing soup kitchens, hospitals, schools, libraries, mosques, and the like. One of the most common forms of charity in medieval Islamic cities was to establish a public drinking fountain, where fresh, sweet water was distributed freely to all passers-by. Such a drinking fountain was commonly known as a sabil, from the common Arabic expression fi sabil allah, literally meaning "in the path of God" and referring to doing something for God charitably or disinterestedly.