Merits of the Helpers in Madinah (Ansaar)
Bukhari :: Book 5 :: Volume 58 :: Hadith 255
Narrated Abu 'Uthman:
I heard that Ibn 'Umar used to become angry if someone mentioned that he had migrated before his father ('Umar), and he used to say, " 'Umar and I came to Allah's Apostle and found him having his midday rest, so we returned home. Then 'Umar sent me again (to the Prophet ) and said, 'Go and see whether he is awake.' I went to him and entered his place and gave him the pledge of allegiance. Then I went back to 'Umar and informed him that the Prophet was awake. So we both went, running slowly, and when 'Umar entered his place, he gave him the pledge of allegiance and thereafter I too gave him the pledge of allegiance,"