Nafi reported,

Ibn Umar intended to perform Hajj during the year of the Haruriyyah's pilgrimage, in the time of Ibn Zubayr . It was said to him, "There is going to be fighting among the people, and we fear they may prevent you from reaching the House."He replied, "Indeed, in the Messenger of Allah you have an excellent example" [Ahzab 33:21]. "I will do as he did. I call you to witness that I have made Umra obligatory upon myself."When he reached the open plain of al-Bayda, he said, "The matter of Hajj and Umra is but one. I call you to witness that I have combined a Hajj with my Umra." He brought along a sacrificial animal which he had bought and garlanded.When he arrived, he performed tawaf around the House and saa between Safa and Marwa, doing nothing beyond that. He did not release himself from any of the restrictions of ihram until the Day of Sacrifice, when he shaved his head and offered his sacrifice. He considered that his initial tawaf had fulfilled the circumambulation for both his Hajj and his Umra.Then he said, "This is exactly what the Prophet ﷺ did."

عن نافع، قال

أراد ابن عمر رضي الله عنهما الحج، عام حجة الحرورية في عهد ابن الزبير رضي الله عنهما، فقيل له: إن الناس كائن بينهم قتال ونخاف أن يصدوك، فقال: {لقد كان لكم في رسول الله أسوة حسنة} [سورة الأحزاب: ٢١] إذا أصنع كما صنع، أشهدكم أني أوجبت عمرة، حتى إذا كان بظاهر البيداء قال: ما شأن الحج والعمرة إلا واحد، أشهدكم أني جمعت حجة مع عمرة. وأهدى هديا مقلدا اشتراه، حتى قدم فطاف بالبيت وبالصفا، ولم يزد على ذلك ولم يحلل من شيء حرم منه حتى يوم النحر، فحلق ونحر، ورأى أن قد قضى طوافه للحج والعمرة بطوافه الأول، ثم قال: كذلك صنع النبي ﷺ.