It wasnarrated from Abu Qatadah that the Messenger of Allah (ﷺ)said:
"Fasting on the Day of 'Arafah, I hope from Allah, expiates forthe sins of the year before and the year after." (RU)
English reference (RU): Vol. 1, Book 7, Hadith 1730 (RU)
Arabic reference (RU): Book 7, Hadith 1802 (RU)