In the tenth year after the Hijrah, the Prophet, peace be upon him, led the pilgrimage for the only time in his life, joined by a very large gathering of Companions. Standing at Arafah, he delivered the address remembered as the Farewell Sermon, whose contents are preserved across several authentic reports.

He declared the life, property and honour of every person sacred. He abolished the blood feuds and the interest-bearing debts of the pre-Islamic age, beginning with those owed to his own family. He urged the good treatment of women, and of those under one's authority. He reminded the people that they would meet their Lord, and be asked about one another. And he stated that no Arab has any superiority over a non-Arab, nor white over black, except by piety. He asked them to convey his words to those who were absent. Around this time the verse was revealed: “This day I have perfected for you your religion and completed My favour upon you”.

Soon after returning to Madinah, he fell ill with a fever. In his final days he led or attended the prayer as long as he was able, and then asked Abu Bakr to lead it in his place. He freed his servants, gave away the little money in the house, and repeatedly urged those around him to guard the prayer, and to take care of the rights of people under their care.

He died in the room of Aishah, on a Monday in the month of Rabi al-Awwal, in the eleventh year after the Hijrah, at the age of about sixty-three. The community was overwhelmed, and some of the strongest Companions could not at first accept that he was gone. Umar stood and denied it. Abu Bakr, arriving from the edge of the city, confirmed the death, and then came out to the people and said: “Whoever used to worship Muhammad — Muhammad is dead. Whoever worships Allah — Allah is alive and never dies,” and he recited: “Muhammad is no more than a messenger; messengers have passed away before him. If he dies or is killed, would you turn back on your heels?” The report is in Sahih al-Bukhari. It is said that it was as though the people had not known the verse until Abu Bakr recited it that day.

What the Prophet left was not wealth, land or a dynasty. His estate was given away as charity. He left a completed revelation, and a documented way of life. He is reported to have said that he left behind two things, the Book of Allah and his Sunnah, and that whoever holds to them will not go astray. The scholarship, law, spirituality and history of Islam that followed are, in large part, the ongoing work of understanding and living by those two.