Sayyiduna Abu Qatadah (may Allah be pleased with him) narrates: A man asked the Prophet (peace and blessings be upon him). He said: O Messenger of Allah (peace and blessings be upon him)! What is your opinion about a person who fasts on the day of Ashura? The Prophet (peace and blessings be upon him) said: It is equal to fasting for a whole year. He asked: What is your opinion about a person who fasts on the day of Arafah? The Prophet (peace and blessings be upon him) said: It wipes out the sins of the previous year and the coming year.