The Book of Fasting (Kitab Al-Sawm)

Muslim :: Book 6 : Hadith 2614

Abu Ayyub al-Ansari (Allah be pleased with him) reported Allah's Messenger (may peace be upon him) as saying: He who observed the fast of Ramadan and then followed it with six (fasts) of Shawwal. it would be as if he fasted perpetually.