Sahih al-Bukhari 1807

Abdullah ibn Muhammad ibn Asma narrated to us; Juwayriya narrated to us, from Nafi, that Ubaydullah ibn Abdullah and Salim ibn Abdullah informed him that, during the nights when the army encamped against Ibn al-Zubayr, they spoke to Abdullah ibn Umar (may Allah be pleased with them both). They said: “It will not harm you if you do not perform Hajj this year, and we fear that you may be kept from reaching the House.” He replied: “We set out with the Messenger of Allah, but the Quraysh disbelievers kept us from the House. The Prophet sacrificed his offering and shaved his head. I call you to witness that I have undertaken Umrah. God willing, I will set out; if I am given access to the House, I will circumambulate it, and if I am prevented from reaching it, I will do as the Prophet did when I was with him.” He entered ihram for Umrah at Dhu al-Hulayfah, then traveled for a while and said: “The two rites have the same ruling. I call you to witness that I have undertaken Hajj together with my Umrah.” He did not leave ihram for either rite until the Day of Sacrifice, and he offered an animal. He used to say: “One does not leave ihram until performing a single circumambulation on the day one enters Mecca.”