Abu Umamah bin Sahl bin Hunaif narrated from some of the companions of the Prophet (s.a.w) that the Prophet (s.a.w) said:
"While I was sleeping I saw people presented before me, and that they were wearing shirts. Some of them (the shirts) reaching their breasts, and some of them reaching below that." He said: "Then 'Umar was presented before me and he was wearing a shirt that was dragging." They said: "How did you interpret that O Messenger of Allah?" He said: "The religion."
English reference: Vol. 4, Book 8, Hadith 2285
Arabic reference: Book 34, Hadith 2454