‘Abdallah b. Shaqiq said that when he asked ‘A'isha whether the Prophet used to fast a whole month she replied, "I never knew him to fast a whole month except Ramadan, nor to refrain from fasting some part of every month till he died."
‘A'isha said, "God’s messenger used to fast to such an extent that we thought he would never break his fast, and he would go without fasting to such an extent that we thought he would never fast. I never saw God’s messenger fast a complete month except in Ramadan, and I never saw him fast more in any month than in Sha'ban." In a version she said he used to fast the whole of Sha'ban, i.e. he would fast all but a little of Sha'ban.
‘Imran b. Husain said that the Prophet asked him, or that he asked a man in ‘Imran’s hearing, “Father of so and so, did you not fast the last day of Sha'ban?" When, he replied that he had not, he said, “If you did not observe a fast, you must fast for two days."*
*To reconcile this tradition with that of Abu Huraira at the foot of p.420 it is suggested that the man had made a vow to observe this fast, or that it was his custom.
Malik said he heard that Ibn ‘Umar used to be asked whether one might fast or pray on behalf of another, and reply, “One may neither fast nor pray on behalf of another.”