Fasting 
Bukhari :: Book 3 :: Volume 31 :: Hadith 224
Narrated 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.
Fasting
Bukhari :: Book 3 :: Volume 31 :: Hadith 224
Narrated 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.