The Farewell Pilgrimage
Muḥammad - (محمد)
Muhammad told his followers that the Angel Gabriel came to him every year to recite the Qur'an with him, but this year he came twice. Muhammad understood this to mean that his time was coming to an end, and thus told his close followers to call all people from various places to join him in his final pilgrimage to Mecca. This occasion marked the first time that Muslims of this number had gathered in one place in the presence of their leader. It has been reported that more than seventy thousand people followed him to Mecca and that on the fourth day of Dhu'l-Hijjah, more than one hundred thousand Muslims had entered Mecca to complete the rites of the Hajj.
Since Mecca had embraced Islam, and the Battle of Tabuk had ended, most of the Arabian Peninsula was under Muhammad's leadership, and there was a record high attendance to the pilgrimage.
It was during this pilgrimage that Muhammad declared the validity of the Mut'ah of Hajj.
The Farewell Sermon 
Muhammad led the pilgrims from Mecca through the Valley of Mina and up to the Mountain of Arafat and then stopped them in the Valley of Uranah. They stood in front of him silently as he sat on his camel and delivered his Farewell Sermon.
See also