The Book of Prayers (Kitab Al-Salat)
Muslim :: Book 4 : Hadith 917
Qaz'a reported: I came to Abu Sa'id al-Khudri and he was surrounded by people. When the people departed from him I said: I am not going to ask you what these people have been asking you. I want to ask you about the prayer of the Messenger of Allah (may peace be upon him). He (Abu Sa'id) said: There is no good for you in this. He (Qaz'a), however, repeated (his demand). He then said: The noon prayer would start and one of us would go to Baqi' and, having relieved himself, would come to his home, then perform ablution and go to the mosque, and (he would find) The Messenger of Allah (may peace be upon him) in the first rak'ah.