The Book of Sacrifices (Kitab Al-Adahi)
Muslim :: Book 22 : Hadith 4851
Abu 'Ubaid, the freed slave of Ibn Azhar, reported that he said 'Id (prayer) with Umar b. al-Khattab, and then said the 'Id (prayer) with 'Ali b. Abu Talib. He (the narrator further) reported: He led us in prayer before delivering the sermon and then addressed the people saying: Allah's Messenger (may peace be upon him) has forbidden you to eat the flesh of your sacrificial animals beyond three nights, so do not eat that.