Hadith on Fasting: Recommendation to fast six days of Shawwal

Abu Ayyub reported: The Messenger of Allah, peace and blessings be upon him, said, “Whoever fasts the month of Ramadan and then follows it with six days of fasting in the month of Shawwal, it will be as if he fasted for the entire year.

Source: Ṣaḥīḥ Muslim 1164

Grade: Sahih (authentic) according to Muslim

عَنْ أَبِي أَيُّوبَ الْأَنْصَارِيِّ رَضِيَ اللَّهُ عَنْهُ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ مَنْ صَامَ رَمَضَانَ ثُمَّ أَتْبَعَهُ سِتًّا مِنْ شَوَّالٍ كَانَ كَصِيَامِ الدَّهْرِ

1164 صحيح مسلم كتاب الصيام باب استحباب صوم ستة أيام من شوال إتباعا لرمضان