The Hajj (Arabic: حج‎ Ḥaǧǧ "pilgrimage", also spelled haj and hadj) is the pilgrimage to Mecca, Saudi Arabia. It is one of the largest pilgrimages in the world, and is the fifth pillar of Islam, a religious duty that must be carried out at least once in their lifetime by every able-bodied Muslim who can afford to do so. The Hajj is a demonstration of the solidarity of the Muslim people, and their submission to God (Allah in the Arabic language).

The pilgrimage occurs from the 8th to 12th day of Dhu al-Hijjah, the 12th and last month of the Islamic calendar. Because the Islamic calendar is a lunar calendar, eleven days shorter than the Gregorian calendar used in the Western world, the Gregorian date of the Hajj changes from year to year. Ihram is the name given to the special spiritual state in which Muslims live while on the pilgrimage.

The Hajj is associated with the life of Islamic prophet Muhammad from the 7th century, but the ritual of pilgrimage to Mecca is considered by Muslims to stretch back thousands of years to the time of Abraham (Ibrahim). Pilgrims join processions of hundreds of thousands of people, who simultaneously converge on Mecca for the week of the Hajj, and perform a series of rituals: Each person walks counter-clockwise seven times around the Kaaba, the cube-shaped building which acts as the Muslim direction of prayer, runs back and forth between the hills of Al-Safa and Al-Marwah, drinks from the Zamzam Well, goes to the plains of Mount Arafat to stand in vigil, and throws stones in a ritual Stoning of the Devil. The pilgrims then shave their heads, perform a ritual of animal sacrifice, and celebrate the three day global festival of Eid al-Adha.

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]}