Musnad Ahmad 1153:1029

Waki' narrated to us, Yazid ibn Ziyad ibn Abi al-Ja'd narrated to us, from 'Abd al-Rahman ibn 'Abis, from his father, from 'Aishah, she said: "We used to lift the trotters (of a slaughtered animal) for the Messenger of Allah, peace and blessings of Allah be upon him, and he would eat them after a month."