TABARANI 3913:
from Abū Ayyūb al-Anṣārī —
[Machine] The Messenger of Allah ﷺ said, "Whoever fasts Ramadan and follows it with six days as if he has fasted the whole year."
الطبراني ٣٩١٣:
عن ابو ايوب الانصاري —
قَالَ رَسُولُ اللهِ ﷺ «مَنْ صَامَ رَمَضَانَ وَأَتْبَعَهُ بِسِتٍّ فَكَأَنَّمَا صَامَ السَّنَةَ كُلَّهَا»