Sahih Muslim Book 30, Hadith Number 5858.
Chapter : Pertaining to the merits of Moses (peace be upon him).
Anas b. Malik reported Allah’s Messenger(may peace be upon him)as saying: I came. And in the narration transmitted on the authority of Haddib (the words are): I happened to pass by Moses on the occasion of the Night journey near the red mound (and found him) saying his prayer in his grave.