Sahih Muslim, Hadith No. 1162: Narrated Abu Qatada (R.A): Allah's Messenger (S.A.W) said, "I seek from Allah that fasting on the day of Arafa may atone for the sins of the preceding and the coming year".

Sahih Muslim, Hadith No. 1162

Narrated Abu Qatada (R.A): Allah's Messenger (S.A.W) said, "I seek from Allah that fasting on the day of Arafa may atone for the sins of the preceding and the coming year".