Sahih Bukhari
Sahih Bukhari Volume 005, Book 057, Hadith Number 009.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 57. Companions of the Prophets
Narated By Aiyub : The Prophet said, "If I were to take a Khalil, I would have taken him (i.e. Abu Bakr) as a Khalil, but the Islamic brotherhood is better."