عَنْ أَبِي أَيُّوبَ الْأَنْصَارِيِّ رَضِيَ اللَّهُ عَنْهُ أَنَّ رَسُولَ اللَّهِ قَالَ: ((مَنْ صَامَ رَمَضَانَ وَسِتًّا مِنْ شَوَّالٍ فَقَدْ صَامَ الدَّهْرَ))
Narrated from Sayyiduna Abu Ayyub Ansari (may Allah be pleased with him), the Messenger of Allah (peace and blessings be upon him) said: Whoever fasts in the month of Ramadan and then follows it with six days of fasting in Shawwal, it is as if he has fasted for the whole year.