question #3 Sahih Muslim 1127d, Book 13, Hadith 157 : What should one do if they are not fasting on the day of Ashura according to Islamic teachings?

Abu Abd al-Rahman, it is the day of ‘Ashura (and you are eating). Upon this he said: Fast was observed on (this day) before the (fasting) in Ramadan was made obligatory, but when it was made obligatory, (fasting on the day of ‘Ashura) was abandoned. So if you are not fasting, then take food.