Musnad Ahmad 27:1944

'Uthman ibn 'Umar narrated to us, Yunus informed us, from al-Zuhri, who said: It reached us that the Messenger of Allah (peace and blessings of Allah be upon him), when he would stone the first Jamrah which is adjacent to the mosque, he would stone it with seven pebbles, saying the takbir with every pebble. Then he would stand in front of it, facing the House (the Ka'bah), raising his hands and supplicating, and he would prolong the standing. Then he would stone the second with seven pebbles, saying the takbir with every pebble. Then he would turn to the left toward the bottom of the valley, and he would stand, facing the Qiblah, raising his hands and supplicating. Then he would proceed until he came to the Jamrah which is at al-'Aqabah, and he would stone it with seven pebbles, saying the takbir at every pebble. Then he would turn away and not stand. Al-Zuhri said: I heard Salim narrating from Ibn 'Umar, from the Prophet (peace and blessings of Allah be upon him) the like of this. And Ibn 'Umar used to do like this.