Fasting 
Bukhari :: Book 3 :: Volume 31 :: Hadith 223
Narrated 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."
Fasting
Bukhari :: Book 3 :: Volume 31 :: Hadith 223
Narrated 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."