Ibn Buraydah narrates from his father (Sayyiduna Buraydah, may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) would eat something before going out for Eid al-Fitr, and on Eid al-Adha he would eat after coming back, and when he came back he would eat from the liver of his sacrifice.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة العيدين / 6161