When Ibrahim (Alaihis salaam) completed the structure of the Ka'bah, Allah (Subhanahu wa ta'ala) commanded him to call the people to Hajj. Ibrahim (Alaihis salaam) pleaded, "O Allah! How shall my voice reach all of those people?" Allah (Subhanahu wa ta'ala) told him that his duty was only to give the call and it was up to Allah to make it reach the people.

Ibrahim (Alaihis salaam) then climbed Mount Arafat and called out in his loudest voice, "O People! Verily Allah has prescribed upon you Hajj, so perform Hajj."

Allah (Subhanahu wa ta'ala) revealed in the Qur'an: "And proclaim the Hajj among mankind. They will come to thee on foot and (mounted) on every camel, lean on account of journeys through deep and distant mountain highways" (Surat Al-Hajj, Ayat 28).