Sheikh `Abd al-Rahmân al-`Ajlân, lecturer at the Grand Mosque in Mecca
Allah made Hajj obligatory in the ninth year of the Hijrah. The Prophet (peace be upon him) performed Hajj in the following year, the tenth year of the Hijrah. This pilgrimage is also known as Hijjah al-Wadâ` because the Prophet (peace be upon him) bade farewell to the people therein. He said: “I may not see you after this year”. Indeed, he passed away a few months later.
The Prophet (peace be upon him) had performed four `Umrahs (lesser pilgrimages): the year after al-Hudaybiyah, al-Qadiyyah, al-Ja`rânah (after allocating the spoils of Hunayn), and the `Umrah which was performed along with his Hajj.
Source: Islam Today