Ali bin Abi Talib (may Allah be pleased with him) said: "Coming to the Eid prayer ground on foot is the Sunnah." Abu Dawud (may Allah have mercy on him) added these words in his narration: "When you return, you may ride."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة العيدين / 6147