Musnad Ahmad 30:2285

Qutaybah narrated to us, he said: Al-Mughirah ibn Abd al-Rahman al-Qurashi narrated to us, from Abu al-Zinad, from al-A'raj, from Abu Hurayrah, who said: The Messenger of Allah, peace and blessings of Allah be upon him, said: "Abraham performed circumcision when he was eighty years old, with the Qadum (adze)."