Musnad Abu Ya'la al-Mawsili 110:108

Abu Ma'mar narrated to us, Abu al-Ahwas narrated to us, from Simak, from Ikrimah, from Ibn Abbas, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Upon every joint of the son of Adam, every day, there is a charity." Then he mentioned the like of this hadith.