Sahih Muslim
The Book of Pilgrimage (Kitab Al-Hajj)
Book Number: 007 / Hadith Number: 2859
Ibn 'Abbas (Allah be pleased with them) 'is reported to have said: The Messenger of Allah (may peace be upon him) put on Ihigm for Hajj. When four days of Dhu'l-Hijja were over, he led the dawn prayer, and when the prayer was complete, he said: He who wants to change it to Umra may do so.