Sahih Muslim
The Book of Pilgrimage (Kitab Al-Hajj)
Book Number: 007 / Hadith Number: 2829
'Imran b. al-Husain (Allah be pleased with him) said: Know well that Allah's Messenger (may peace be upon him) combined 'Hajj and 'Umra, and nothing was revealed in the Book (to abrogate it), and the Messenger of Allah (may peace be upon him) too did not forbid us from (combining) them. And whatever a person said was out of his personal opinion.