Sahih Muslim
The Book of Sacrifices (Kitab Al-Adahi)
Book Number: 022 / Hadith Number: 4850
Abu Ubaid reported: I was with 'Ali b. Abi Talib on the occasion of the 'Id day. He started with the 'Id prayer before delivering the sermon, and said: Allah's Messenger (may peace be upon him) forbade us to eat the flesh of our sacrificial animals beyond three days.