Musnad Ahmad 27:873

'Abd al-Wahhab narrated to us, from Ayyub, from Nafi', from Ibn 'Umar, that he would not abandon Hajj or 'Umrah. 'Abdullah ibn 'Abdullah entered upon him and said: "I do not feel secure that there will not be fighting among the people this year, so if you were to stay behind..." He said: "The Messenger of Allah (ﷺ) performed Hajj, and the disbelievers of Quraysh stood between him and the House. If they stand between me and it, I will do as the Messenger of Allah (ﷺ) did. Allah, Blessed and Exalted is He, says: 'There has certainly been for you in the Messenger of Allah an excellent pattern' [Al-Ahzab: 21]." Then he said: "I call you to witness that I have made 'Umrah obligatory (upon myself)." Then he traveled until, when he was at al-Bayda', he said: "By Allah, I do not see their way (the way of Hajj and 'Umrah) as anything but one. I call you to witness that I have made Hajj obligatory along with my 'Umrah." Then he performed one circumambulation (Tawaf) for both of them.