Umar bin Khattab reported,

One day, while we were sitting with the Messenger of Allah ﷺ, a man suddenly appeared before us. His clothes were intensely white, his hair intensely black, and no trace of travel could be seen on him, yet none of us recognized him. He came and sat before the Prophet ﷺ, pressing his knees against the Prophet's knees and placing his palms on his own thighs.He said, "Muhammad, tell me about Islam."The Messenger of Allah replied, "Islam is to testify that there is no god but Allah and that Muhammad is the Messenger of Allah ﷺ, to establish the prayer, to give the zakat, to fast Ramadan, and to perform pilgrimage to the House if you are able to find a way to it."The man said, "You have spoken the truth!"And the hadith continues at length.

Azami 4715

Sahih

عن عمر بن الخطاب، قال

بينما نحن عند رسول الله ﷺ ذات يوم إذ طلع علينا رجل شديد بياض الثياب شديد سواد الشعر لا يرى عليه أثر السفر ولا يعرفه منا أحد حتى جلس إلى النبي ﷺ فأسند ركبتيه إلى ركبتيه، ووضع كفيه على فخذيه وقال: يا محمد، أخبرني عن الإسلام؟ فقال رسول الله: الإسلام أن تشهد أن لا إله إلا الله وأن محمدا رسول الله ﷺ، وتقيم الصلاة، وتؤتي الزكاة، وتصوم رمضان، وتحج البيت إن استطعت إليه سبيلا. قال صدقت! الحديث بطوله.

الأعظمي 4715صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Hajj
Chapter
Obligation of Hajj, its virtue, and its conditions
Section
Affirmation of the obligation of Hajj, that it is once, and what is beyond that is voluntary
Numbering
Jami al-Kamil 4715 (2nd edition)
Azami 4715