Salam Ansar, The site did not state where it was Bukhari or Muslim:
http://jamaat.org/Isharat/1999/0399.html
I have been looking but cant find anything to specific, here are two things that may be of interest, one link and a hadeeth.
http://www.islamonline.net/fatwa/eng...hFatwaID=97509
You have the honour of being among the earliest who accepted Islam as well as being a relation of the Prophet of Allah. By God! If you are entrusted with Khilafat, promise that you will rule with justice and if ‘Uthman (rta) is made the Khalifah, you shall listen to him and obey him. (Ibn Sa‘ad, Al-Tabaqatu’l-Kubra, vol. 3, [Beirut: Dar Sadir, 1960], p. 339)
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