Musnad Abu Ya'la al-Mawsili 2:80

Muhammad ibn Bashar narrated to us, Abu Dawud, the author of al-Tayalisi, narrated to us, from Ja'far ibn Muhammad al-Makhzumi, who said: I saw Muhammad ibn 'Abbad ibn Ja'far before the Black Stone, and he prostrated upon it. He said: I saw the Messenger of Allah, may Allah bless him and grant him peace, doing it.