Sayyiduna al-Bara' bin Azib (may Allah be pleased with him) says: The Messenger of Allah (peace and blessings be upon him) addressed us on the Day of Sacrifice after the prayer and said: "Whoever prays as we pray and sacrifices as we sacrifice has attained the sacrifice, and whoever sacrifices before the prayer, that is a goat for meat." Sayyiduna Abu Burdah bin Niyar (may Allah be pleased with him) stood up and said: O Messenger of Allah! I sacrificed before coming to the prayer, and I knew that today is a day of eating and drinking, so I hurried; I ate myself and also fed my family and neighbors. The Prophet (peace and blessings be upon him) said: "That is a goat for meat." He said: I have a young goat which is better than two goats for meat; will it suffice for me? He said: "Yes, but it will not suffice for anyone after you."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة العيدين / 6262