Sayyiduna al-Bara' (may Allah be pleased with him) narrates from his maternal uncle Sayyiduna Abu Burdah (may Allah be pleased with him), who said: On the Day of Sacrifice I took the hand of the Prophet (peace and blessings be upon him) and took him to my house, and I said to the slave-girl: Feed us from the meat of your sacrifice. He (peace and blessings be upon him) said: "This is not a sacrifice; it is merely a goat for meat. The sacrifice is only after the prayer." I said: O Messenger of Allah, we have a one-year-old goat that we raised ourselves; shall I sacrifice it? He (peace and blessings be upon him) said: "Yes, but it will not suffice for anyone after you."
Hadith Referenceالمعجم الكبير للطبراني / باب الهاء / 18725