It wasnarrated that Rabi'ah bin Ghaz asked 'Aishah about the fastingofthe Messenger of Allah (ﷺ). She said:
"He used to fast all ofSha'ban, until he joined it to Ramadan." (ID)
English reference (ID): Vol. 1, Book 7, Hadith 1649 (ID)
Arabic reference (ID): Book 7, Hadith 1718 (ID)