It wasnarrated from Abu Qatadah that the Messenger of Allah (ﷺ)said:
"Fasting the day of 'Ashura', I hope, will expiate for the sinsof the previous year." (FR)
English reference (FR): Vol. 1, Book 7, Hadith 1738 (FR)
Arabic reference (FR): Book 7, Hadith 1810 (FR)