Nafi reported,

Ibn Umar intended to perform Hajj the year Hajjaj laid siege to Ibn Zubayr. He was told, "Fighting is about to break out among the people, and we fear they will prevent you from reaching the House."He replied, "In the Messenger of Allah you have a beautiful example" [Ahzab 33:21]. "I will do as the Messenger of Allah ﷺ did. I call you to witness that I have made Umra obligatory upon myself."Then he set out, and when he reached the open plain of Bayda, he said, "Hajj and Umra are but one. I call you to witness that I have made Hajj obligatory upon myself along with my Umra."He brought along a sacrificial animal that he had purchased at Qudayd, and he did nothing more than that. He did not slaughter, did not come out of ihram from anything forbidden to him, did not shave, and did not shorten his hair until the Day of Sacrifice arrived. Then he slaughtered and shaved, considering that his first tawaf had fulfilled the tawaf of both Hajj and Umra.Ibn Umar said, "This is what the Messenger of Allah ﷺ did."

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عن نافع

أن ابن عمر رضي الله عنهما أراد الحج عام نزل الحجاج بابن الزبير فقيل له إن الناس كائن بينهم قتال وإنا نخاف أن يصدوك فقال {لقد كان لكم في رسول الله إسوة حسنة} إذا أصنع كما صنع رسول الله ﷺ إني أشهدكم أني قد أوجبت عمرة ثم خرج حتى إذا كان بظاهر البيداء قال ما شأن الحج والعمرة إلا واحد أشهدكم أني قد أوجبت حجا مع عمرتي وأهدى هديا اشتراه بقديد ولم يزد على ذلك فلم ينحر ولم يحل من شيء حرم منه ولم يحلق ولم يقصر حتى كان يوم النحر فنحر وحلق ورأى أن قد قضى طواف الحج والعمرة بطوافه الأول وقال ابن عمر رضي الله عنهما كذلك فعل رسول الله ﷺ