Narrated Nafi`:

One of `Abdullah's sons said to `Abdullah (bin `Umar) "I wish you would stay this year (and not perform Hajj) as I am afraid that you will not be able to reach the Ka`ba." On that he (i.e. `Abdullah bin `Umar) said, "We went out with the Prophet (for `Umra), and when the Quraish infidel intervened between us and the Ka`ba, the Prophet (ﷺ) slaughtered his Hadi and shaved (his head), and his companions cut short their hair." Then `Abdullah bin `Umar said, "I make you witness that I have intended to perform `Umra and if I am allowed to reach the Ka`ba, I will perform the Tawaf, and if something (i.e. obstacles) intervene between me and the Ka`ba, then I will do what Allah's Messenger (ﷺ) did." Then after going for a while, he said, "I consider the ceremonies (of both `Umra and Hajj as one and the same, so I would like you to witness that I have intended to perform Hajj along with my `Umra." So he performed only one Tawaf and one Sai (between Safa and Marwa) and finished the Ihram of both Umra and Hajj).