Sahih Bukhari Book 31. Fasting

Narated By ‘Aisha : Quraish used to fast on the day of ‘Ashura’ in the Pre-lslamic period, and Allah’s Apostle too, used to fast on that day. When he came to Medina, he fasted on that day and ordered others…

Narated By Humaid bin ‘Abdur Rahman : That he heard Muawiya bin Abi Sufyan on the day of ‘Ashura’ during the year he performed the Hajj, saying on the pulpit, “O the people of Medina! Where are your Religious Scholars?…

Narated By Ibn ‘Abbas : The Prophet came to Medina and saw the Jews fasting on the day of Ashura. He asked them about that. They replied, “This is a good day, the day on which Allah rescued Bani Israel…

Narated By Abu Musa : The day of ‘Ashura’ was considered as ‘Id day by the Jews. So the Prophet ordered, “I recommend you (Muslims) to fast on this day.”

Narated By Ibn ‘Abbas : I never saw the Prophet seeking to fast on a day more (preferable to him) than this day, the day of ‘Ashura’, or this month, i.e. the month of Ramadan.

Narated By Salama bin Al-Akwa : The Prophet ordered a man from the tribe of Bani Aslam to announce amongst the people that whoever had eaten should fast the rest of the day, and whoever had not eaten should continue…