Ibn Abbas (may Allah be pleased with them both) said that the Messenger of Allah (peace and blessings be upon him) "forbade fasting on the day of Arafah on the plain of Arafat."
This is how al-Harith bin Ubayd narrated it; what is preserved (mahfuz) is from Ikrimah, from Abu Hurayrah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9471