Musnad Ahmad 25:251

Waki’ narrated to us, Sufyan narrated to us, from Salamah, from al-Hasan al-‘Arani, from Ibn Abbas, who said: We were sent ahead by the Messenger of Allah (peace and blessings of Allah be upon him)—we were young boys of Banu ‘Abd al-Muttalib—from Jam’ [Muzdalifah] at night on our small donkeys. He began to pat our thighs and say: "O my sons, do not stone the Jamrah until the sun has risen."