Nafi reported,

Abdullah bin Abdullah and Salim bin Abdullah reported that they both spoke to Abdullah bin Umar when the army laid siege to Ibn Zubayr, before he was killed. They said to him, "It would not harm you if you did not perform Hajj this year. We fear that you may be prevented from reaching the House."He replied, "We set out with the Messenger of Allah ﷺ, and the disbelievers of Quraysh blocked us from reaching the House. So the Messenger of Allah ﷺ sacrificed his offering, shaved his head, and I bear witness to you that I have committed myself to Umrah, if Allah wills. I will set out, and if I am given clear access to the House, I will perform tawaf, but if I am prevented from reaching the House, I will do what the Messenger of Allah ﷺ did when I was with him."Then he traveled for a while and said, "Their matter is one and the same. I bear witness to you that I have committed myself to Hajj along with my Umrah."He did not exit the state of ihram from either of them until he came out of it on the Day of Sacrifice, and he offered a sacrificial animal.

Nasai 2862

Sahih

أخبرنا محمد بن عبد الله بن يزيد المقرئ قال حدثنا أبي قال حدثنا جويرية

عن نافع

أن عبد الله بن عبد الله وسالم بن عبد الله أخبراه أنهما كلما عبد الله بن عمر لما نزل الجيش بابن الزبير قبل أن يقتل فقالا لا يضرك أن لا تحج العام إنا نخاف أن يحال بيننا وبين البيت قال خرجنا مع رسول الله ﷺ فحال كفار قريش دون البيت فنحر رسول الله ﷺ هديه وحلق رأسه وأشهدكم أني قد أوجبت عمرة إن شاء الله أنطلق فإن خلي بيني وبين البيت طفت وإن حيل بيني وبين البيت فعلت ما فعل رسول الله ﷺ وأنا معه ثم سار ساعة ثم قال فإنما شأنهما واحد أشهدكم أني قد أوجبت حجة مع عمرتي فلم يحلل منهما حتى أحل يوم النحر وأهدى

النسائي 2862صحيح
Contents
Reference
Commentary
Ayat
Collection
Sunan Nasai Sughra
Book
Rituals of Hajj
Chapter
Those who are prevented by an enemy
Numbering
Darussalam 2862
Nasai 2862