Musnad Ahmad 292:5

Ya'qub narrated to us, he said: My father narrated to us, from Muhammad ibn Ishaq, he said: Muhammad ibn Ali ibn al-Husayn, Abu Ja'far, and Abu Ishaq ibn Yasar narrated to me, from Abdullah ibn Khabbab, the freed slave of Banu Adi ibn al-Najjar, from Abu Sa'id al-Khudri, who said: The Messenger of Allah (peace and blessings of Allah be upon him) had forbidden us from eating the meat of our sacrificial animals beyond three days. He said: So I went out on a journey, then I returned to my family, and that was days after the Adha. He said: My wife brought me some chard in which she had placed some dried meat. I said to her: "Where did you get this dried meat from?" She said: "From our sacrificial animals." He said: I said to her: "Did the Messenger of Allah (peace and blessings of Allah be upon him) not forbid us from eating them beyond three days?" He said: She replied: "He has indeed granted a concession to the people after that." He said: I did not believe her, until I sent for my brother, Qatadah ibn al-Nu'man, and he was a veteran of Badr, to ask him about that. He said: So he sent word to me: "Eat your food, for she has spoken the truth. The Messenger of Allah (peace and blessings of Allah be upon him) has indeed granted a concession to the Muslims regarding that."