Sunan Abi Dawud Book 42, Hadith 34
I said to my father: Which of the people after the Messenger of Allah (ﷺ) is best? He replied: Abu Bakr. I then asked: Who comes next? He said: ‘Umar. I was then afraid of asking him who came next, and he might mention ‘Uthman, so I said: You came next, O my father? He said: I am only a man among the Muslims.
When the Messenger of Allah (ﷺ) was alive, we used to say: The most excellent member of the community of the Prophet (ﷺ) after himself is Abu Bakr, then ‘Umar, then 'Uthman.
I heard Sufyan say: If anyone thinks that ‘All (Allah be pleased with him) was more deserving for the Caliphate than both of them, he imputed error to Abu Bakr, ‘Umar, the Muhajirun (Immigrants), and the Ansar (Helpers) Allah be pleased with all of them. I think that with this (belief) none of his action will rise to the heaven.