Musnad Abu Ya'la al-Mawsili 110:100

Muhammad ibn Abd al-Rahman ibn Sahm narrated to us, Abdullah ibn al-Mubarak and Isa ibn Yunus narrated to us, from Awf al-A'rabi, from Ziyad ibn Husayn, from Abu al-Aliyah, from Ibn Abbas, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said to me on the morning of the Jamrah: "Come, pick up for me." So I picked up for him pebbles of the size used for throwing (al-khadhf). When he placed them in his hand, he said: "Yes, with the likes of these. Yes, with the likes of these. And beware of extremism in religion, for those who were before you were only destroyed by extremism in religion."