Musnad Ahmad 28:193

Abu Mu'awiyah narrated to us, Hajjaj narrated to us, from 'Amr ibn Shu'ayb, from his father, from his grandfather, who said: I saw the Messenger of Allah (peace and blessings of Allah be upon him) stop at the second Jamrah for longer than he stopped at the first Jamrah. Then he came to the Jamrat al-Aqabah and threw pebbles at it, and he did not stop at it.