Sayyiduna Ayyub (Allah be pleased with him) relates that the Messenger of Allah (blessings and peace be upon him, his family, and companions) said, “Whoever fasts Ramadan and follows it with six days from Shawwal it is as if they fasted the entire year.” [Muslim, Abu Dawud, Tirmidhi, and Ibn Majah; Ahmad transmitted it from Jabir, Muntaqa]