Abu Ayyoub (Radiallaho Anho) reported
that the Messenger of Allah, salla Allahu alaihi wa sallam said
"Whoever fasts the month of Ramadhan and then follows it by
fasting six days during the month of Shawwal will be rewarded
as if he had fasted the entire year.
[Muslim, at-Tirmithi, Ibn Majah, Abu Dawood].
