Riyad as-Salihin
Riyad as-Salihin 1254
The Desirability of Fasting six Days in the Month of Shawwal
Arabic hadith text
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)).
Translation
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].