Hazrat Ibn Umar (may Allah be pleased with them both) was asked about fasting on the day of Arafah. He replied: I performed Hajj with the Prophet (peace and blessings of Allah be upon him), and he did not fast on that day. I performed Hajj with Hazrat Abu Bakr Siddiq, and he also did not fast on that day. I performed Hajj with Hazrat Umar, and he too did not fast on that day. I performed Hajj with Hazrat Uthman, and he also did not fast on that day. And I myself do not fast on that day. As for the rest, I neither command you to do so nor forbid you from it.