Musnad Ahmad 1017:50

Yunus narrated to us, 'Aqbah bin 'Abdullah al-Rifa'i narrated to us, 'Abdullah bin Buraydah narrated to me, from his father, who said: The Messenger of Allah (may Allah bless him and grant him peace) would not go out on the day of Fitr until he had eaten, and he would not eat on the day of Adha until he returned, so he would eat from his sacrifice.