Sahih Al Bukhari Hadith Number 1516

Narrated ‘Aishah: The Prophet (peace be upon him) sent my brother, ‘Abdur Rahman with me to Tan’im for the ‘Umra, and he made me ride on the packsaddle (of a camel). ‘Umar said, “Be ready to travel for Hajj as it (Hajj) is one of the two kind of Jihad”.

25  Hajj (Pilgrimage)
Hadith number 1516
Volume no 2
Chapter: 3 (To go for Hajj on a pack-saddle (of a camel)