Sa'id bin Jubayr (may Allah have mercy on him) narrates: I came to Ibn Abbas (may Allah be pleased with them both) while he was eating a pomegranate at Arafah, and he narrated that the Messenger of Allah (peace and blessings be upon him) "did not fast at Arafah."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8387