Musnad Abu Ya'la al-Mawsili 162:13

Abu Bakr narrated to us, Hafs narrated to us, from Ja'far, from his father, from Ali ibn al-Husayn, from Ibn Abbas, from al-Fadl ibn Abbas: That the Prophet, peace and blessings of Allah be upon him, did not cease reciting the Talbiyah until he threw [pebbles at] Jamrat al-Aqabah. He threw at it seven pebbles, saying "Allahu Akbar" with every pebble.