It wasnarrated that 'Aishah said:
"The Messenger of Allah (ﷺ) usedtofast 'Ashura', and he ordered (others) to fast it too." (JA)
English reference (JA): Vol. 1, Book 7, Hadith 1733 (JA)
Arabic reference (JA): Book 7, Hadith 1805 (JA)