عن أبي أيوب رضي الله عنه أن رسول الله صلى الله عليه وسلم قال‏:‏ ‏"‏من صام رمضان ثم أتبعه بست من شوال كان كصيام الدهر‏"‏ ‏(‏‏(‏رواه مسلم‏)‏‏)‏‏.‏

Abu Ayyub (May Allah be pleased with him) reported

The Messenger of Allah (ﷺ) said, "He who observes As-Saum (the fasts) in the month of Ramadan, and also observes As-Saum for six days in the month of Shawwal, it is as if he has observed As-Saum for the whole year."[Muslim].