Musnad Ahmad 1153:945

'Abd al-Razzaq narrated to us, he said: Sufyan informed us, from 'Abd al-Rahman ibn 'Abis, from his father 'Abis ibn Rabi'ah, from 'Aishah, he said: We asked her, "Did the Messenger of Allah, peace and blessings of Allah be upon him, forbid that the meat of the sacrificial animals be eaten after three [days]?" She said: "He did not say that except in a year in which the people were hungry, so he wanted the rich to feed the poor. And we used to store the trotters, and we would eat them after fifteen [days]." I said: "What compelled you to do that?" She laughed and said: "The family of Muhammad, peace and blessings of Allah be upon him, did not eat their fill of bread with condiment for three nights, until he joined Allah, the Mighty and Majestic."