Hazrat ‘Abdur Rahmaan (radhiyallahu ‘anhu) thereafter wore the turban that Rasulullah (sallallahu ‘alaihi wasallam) had tied on his head, he strapped on his sword and went with Hazrat ‘Ali (radhiyallahu ‘anhu) and Hazrat ‘Uthmaan (radhiyallahu ‘anhu) to the musjid. Hazrat ‘Abdur Rahmaan (radhiyallahu ‘anhu) sent a message to the eminent Sahaabah of the Muhaajireen and Ansaar summoning them, and also instructed for a general announcement to be made, calling the people to the musjid. Accordingly, people began to come to the musjid, forming rows, until the musjid was filled with people.

Hazrat ‘Uthmaan (radhiyallahu ‘anhu) could not find any place to sit and thus, on account of his high level of hayaa, sat behind all the people in the musjid.

Hazrat ‘Abdur Rahmaan (radhiyallahu ‘anhu) then ascended the mimbar of Rasulullah (sallallahu ‘alaihi wasallam) and stood on the step which Rasulullah (sallallahu ‘alaihi wasallam) would sit on. He stood there for a lengthy period and made a long du‘aa which the people could hear. He then addressed the people saying, “O people! I have asked you (regarding Hazrat ‘Ali (radhiyallahu ‘anhu) and Hazrat ‘Uthmaan (radhiyallahu ‘anhu)) in private and in public, in pairs and individually, and I found that you did not equate anybody to these two Sahaabah.”

Hazrat ‘Abdur Rahmaan (radhiyallahu ‘anhu) then held the hand of Hazrat ‘Uthmaan (radhiyallahu ‘anhu) and declared him to be the Khalifah. He thereafter made Hazrat ‘Uthmaan (radhiyallahu ‘anhu) sit on the step of the mimbar below him so that the people could come to him and pledge their allegiance. From all the people, it was Hazrat ‘Ali (radhiyallahu ‘anhu) who came first and pledged his allegiance to Hazrat ‘Uthmaan (radhiyallahu ‘anhu).

(Al-Bidaayah-wan-Nihaayah vol 7 pg. 297-298)