Musnad Ahmad 541:19

Ibrahim ibn Khalid narrated to us, he said: Rabah narrated to us, from Ma'mar, from Asim ibn Sulayman, from Ja'far ibn al-Muttalib—and he was a man from the kin of Amr ibn al-Aas—he said: He invited a Bedouin to food, and that was one day after the sacrifice (Eid al-Adha). The Bedouin said: "I am fasting." He said to him: "Amr ibn al-Aas invited a man to food on this day, and he said: 'I am fasting.' So Amr said: 'Indeed, the Messenger of Allah, peace and blessings of Allah be upon him, forbade fasting on this day.'"