The Farewell Pilgrimage

In this year, (10 A.H.) the Holy Prophet performed his last pilgrimage, details of which are fairly well-known. During his journey back, the Holy Prophet stopped at Ghadir Khum.
Al-Nasa'i in Kitabul Khasa'is narrates a tradition from Zaid ibn al-Arqam on the authority of Abu al-Tufail which runs thus:
Returning from the Farewell Pilgrimage, the Prophet camped at Ghadir Khum. He ordered a pulpit to be made for him. Once the pulpit had been made,he graced it and said, "I have been called back by the Lord, and I have submitted to His orders. Now I leave among you two valuable things, one of them is the Qur'an and the other is my progeny. These shall not separate from each other till they meet me together at the Kawthar in Heaven; therefore, be careful and guard yourselves in your dealings with the Quean and with my progeny after me." Then the Prophet added, "Hearken! Allah is my Master, and I am the master of the believers." Then he raised 'Ali's hand and said, "'Ali is the Master of whoever accepts me as his master. O Lord! Befriend whoever befriends 'Ali and alienate Yourself from whoever alienates 'Ali! "
Abu al-Tufail says:
"When I heard this tradition, I inquired from Zaid ibn al-Arqam: 'Did you hear the Prophet saying these words?' Zaid ibn al-Arqam said, 'Not only I but all those who surrounded the pulpit (did so). They had seen with their own eyes that the Prophet was speaking those words, and they heard them with their own ears. "'
According to another tradition quoted by al-Nasa'i, the Prophet stood up and, having praised the Lord and enumerated His mercies, he asked the gathering:
"My people! Do you not know that I have more authority over you than you yourselves have?"
All of them replied:
"Yes, we bear witness to the fact that you have more authority over us than we have ourselves."
Then the Prophet held 'Ali by the hand and said:
"Ali is the Master of anyone whose master I am."
This incident took place on the 18th of Dhu-Hijjah, 10 A.H.

Prophet's Illness and Usamah's Expedition

In Tarikh of Abul-Fida, it is stated that:
"After his return from the Farewell Pilgrimage, the Prophet resided at Medina till the close of the 10th year of Hijrah. In Muharram of 11 A.H., the Prophet fell ill. Then he called all his wives at the residence of Maimunah, Mother of the Faithful, where he was staying at that time, requesting them to permit him to remain at the residence of any one particular wife from among them. All of them allowed him to stay during the period of his illness at'Ayishah's."
Ibn al-Wardi writes in his history that during his illness, the Prophet commissioned an army to be led by Usamah son of the late Zaid ibn Harithah to march to Mu'ta in order to avenge the death of his father. The Prophet insisted upon its immediate departure.
On the next day, in spite of his serious condition, the Prophet personally prepared a flag and handed it over to Usamah saying, "Go in the Name of Allah and fight the infidels in His Name." Usamah went out and handed over the standard to Buraidah ibn al-Khusaib whom he appointed as the army's standard-bearer. Having left Medina, he stopped at a village named Jarf which is close to Medina and the army gathered there. The Prophet had also ordered that barring 'Ali, all other principal Immigrants and Helpers, including Abu Bakr, 'Umar, Uthman, Sa'ad ibn Abi Waqqas, Abu Ubaidah ibn al jarrah and others, should accompany Usamah. Some companions felt insulted at the Prophet's appointing the son of a freed slave to lead the senior Immigrants and Helpers, so they started grumbling and criticizing. When the news reached the Prophet, he felt dismayed. Despite his fever and headache, he angrily came out of his residence, mounted the pulpit and declared:
"O people! What is this you are saying on Usamah's appointment as the commander of the army? You talked in a similar manner when Usamah's father was commissioned to lead the army in the battle of Mu'ta. By Allah!, Usamah deserves to be a commander and his father also deserved the leadership of the army. "

The Farewell Pilgrimage

Shahristani, in his book Kitabul Milal wan Nihal, and Nawwab Siddiq Hasan Khan in his book Hujajul Karamah, state that the Prophet ordered his companions thus:
"Make haste in joining Usamah's legion. May Allah curse whoever fags behind Usamah's army."
In Madarijun-Nubuwwah, the following is stated:
"Then, in accordance with the orders of the Prophet, Usamah went to the camp and ordered the army to march. When he was about to mount his steed, his mother informed him that the Prophet was in the agony of death. Receiving this news, Usamah and other companions went back. Abu Bakr and 'Umar were still in Medina; they had not joined the army camp..."