Zakāt (Arabic: زكاة‎ [zæˈkæː], "that which purifies" or "alms"), one of the Five Pillars of Islam, is the giving of a fixed portion of one's wealth to charity, generally to the poor and needy.

Zakat, a practice initiated by Muhammed himself, has played an important role throughout Islamic history. Initially, Muhammed instituted zakat as a voluntary, individual offering, but during his lifetime certain forms of zakat have been declared obligatory. The caliph Abū Bakr, believed by Sunni Muslims to be Muhammed's successor, was the first to institute a statutory zakat system. The third caliph, Uthman ibn Affan (who reigned from 644–656) significantly altered the zakat collection protocol, by decreeing that only "apparent" wealth was taxable, which had the effect of limiting zakat to mostly being paid on agricultural land and produce. Ultimately, the practice of state-administered zakat was very short-lived, ending with the reign of Umar bin Abdul Aziz from 717–720 A.D.

Zakat is considered to be a religious duty, and is expected to be paid by all practicing Muslims who have the financial means (nisab). In addition to their zakat obligations, Muslims are encouraged to make voluntary contributions (sadaqat). The zakat is not collected from non-Muslims, although they are sometimes required to pay the jizyah tax.

Hamza Yusuf Hanson is an American Islamic scholar, and (with Zaid Shakir and Hatem Bazian) is co-founder of Zaytuna College in Berkeley, California, United States. He is a convert to Islam, and is one of the signatories of A Common Word Between Us and You, an open letter by Islamic scholars to Christian leaders, calling for peace and understanding. He has described the 9/11 attacks as "an act of 'mass murder, pure and simple'". Condemning the attacks, he has also stated "Islam was hijacked ... on that plane as an innocent victim".The Guardian newspaper in the United Kingdom reported that he "is arguably the west's most influential Islamic scholar" and added that "many Muslims find his views hard to stomach."

Hamza Yusuf was born to two academics in Washington State and raised in Northern California. In 1977, he became Muslim and subsequently traveled to the Muslim world and studied for ten years in the United Arab Emirates, Saudi Arabia, as well as North and West Africa. Hamza Yusuf spent four years studying in the United Arab Emirates and elsewhere in the Middle East. Later he traveled to West Africa and studied in Mauritania, Medina, Algeria, and Morocco under such scholars as Murabit al Haaj; Baya bin Salik, head of the Islamic court in Al-'Ain, United Arab Emirates; Muhammad Shaybani, Mufti of Abu Dhabi; Hamad al-Wali; and Muhammad al-Fatrati of Al Azhar University in Cairo, Egypt.^{[citation needed]} After more than a decade abroad, he returned to the United States and earned degrees in nursing from Imperial Valley College and religious studies at San José State University.^{[citation needed]}