Abu Dawud Book 14, Hadith Number 3176.

Narated By AbuBakrah : Uyaynah ibn AbdurRahman reported on the authority of his father that he attended the funeral of Uthman ibn Abul’As. He said: We were walking slowly. AbuBakrah then joined us and he raised his flog at us and said: You have seen us when we were with the Apostle of Allah (PBUH). We were walking quickly.