Musnad Abu Ya'la al-Mawsili 139:9

Wahb narrated to us, Khalid informed us, from al-Taymi, from Anas: Some of the companions of the Prophet, may Allah bless him and grant him peace, informed me that the Prophet, may Allah bless him and grant him peace, on the night he was taken on the Night Journey (Isra), passed by Musa while he was praying in his grave.