What it is
Zakat is one of the five pillars of Islam, the core practices of the faith. The word comes from an Arabic root associated with growing, increasing and purifying. Once a Muslim’s wealth has reached a minimum threshold, called the nisab, and a lunar year has passed, they owe 2.5 percent of their qualifying wealth.
The Qur’an names who may receive it, in verse 9:60: the poor, the needy, those who collect and administer it, those whose hearts are to be won over, the freeing of people from slavery, people in debt, the cause of God, and stranded travelers. Rules about giving to relatives differ between schools of Islamic law. The National Zakat Foundation notes that eligible siblings and other relatives may receive zakat, while restrictions apply to close relatives whom the giver must support. At the end of Ramadan, Muslims who have the means also give zakat al-fitr, a gift of food made before the prayer that marks the festival of Eid.
Sadaqah
Sadaqah is voluntary charity, given in any amount and at any time. It is not limited to money: the charity Islamic Relief Worldwide notes that a smile or a helping hand can count as sadaqah.
One form is singled out. In a saying recorded in the collection Sahih Muslim, the Prophet Muhammad taught that when a person dies their deeds come to an end, except three: a recurring charity, knowledge that benefits others, and a pious child who prays for them. That recurring charity, sadaqah jariyah, covers gifts that go on helping, such as a well, a school, a hospital, a planted tree or a skill taught to someone.
The waqf, or charitable endowment, gives that idea an institutional form. A donor sets aside an asset, such as land, a building or cash, so that the asset stays whole and its returns go to good works. The legal form appears to date from the ninth century, and within about a hundred years endowments were supporting places of learning and hospitals across the Islamic world.
Through the source lens
Charitology’s depth scale is a modern frame, and zakat has its own logic of obligation and purification. Still, the recipients the Qur’an names run from relief for the poor to the repair of a life, as in clearing a debt or ending someone’s bondage. Sadaqah jariyah and the waqf reward giving that lasts, the kind that builds and sustains institutions. Zakat is the duty, and sadaqah in all its forms is the voluntary good built on top of it.