From Sahih Bukhari (Hadith 4394):
Narrated `Adi bin Hatim:We came to `Umar in a delegation (during his rule). He started calling the men one by one, calling each by his name. (As he did not call me early) I said to him. "Don't you know me, O chief of the Believers?" He said, "Yes, you embraced Islam when they (i.e. your people) disbelieved; you have come (to the Truth) when they ran away; you fulfilled your promises when they broke theirs; and you recognized it (i.e. the Truth of Islam) when they denied it." On that, `Adi said, "I therefore don't care
Reference: Bukhari 4394