Abdullah bin Umar reported,

When he set out for Makkah to perform Umra during the time of civil strife, he said, "If I am barred from reaching the House, I will do as we did with the Messenger of Allah ﷺ." So he entered the state of ihram for Umra, because the Messenger of Allah ﷺ had entered ihram for Umra in the year of Hudaybiyah.Then Abdullah reconsidered his situation and said, "The two matters are one and the same." He then turned to his companions and said, "The two matters are nothing but one. I call you to witness that I have made Hajj obligatory upon myself along with the Umra."He proceeded until he arrived at the House, where he performed a single tawaf, considered that sufficient for both, and offered a sacrificial animal.

Azami 5366

Sahih

عن عبد الله بن عمر، أنه قال

- حين خرج إلى مكة معتمرا في الفتنة: إن صددت عن البيت صنعنا كما صنعنا مع رسول الله ﷺ فأهل بعمرة من أجل أن رسول الله ﷺ أهل بعمرة عام الحديبية، ثم إن عبد الله نظر في أمره فقال: ما أمرهما إلا واحد، ثم التفت إلى أصحابه: فقال: ما أمرهما إلا واحد أشهدكم أنني قد أوجبت الحج مع العمرة، نفذ حتى جاء البيت فطاف طوافا واحدا ورأى ذلك مجزيا عنه وأهدى.

الأعظمي 5366صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Hajj
Chapter
Umrah
Section
Obligation of Umrah
Numbering
Jami al-Kamil 5366 (2nd edition)
Azami 5366