Aisha said, "The Messenger of Allah ﷺ used to fast so much that we would say he never breaks his fast, and he would go without fasting so much that we would say he never fasts. I never saw the Messenger of Allah ﷺ complete an entire month of fasting except for Ramadan, and I never saw him fast more in any month than he did in Shaban."
أنها قالت: كان رسول الله ﷺ يصوم حتى نقول: لا يفطر، ويفطر حتى نقول: لا يصوم. وما رأيت رسول الله ﷺ استكمل صيام شهر قط إلا رمضان. وما رأيته في شهر أكثر صياما منه في شعبان.
Malik narrated it in Siyam (56) from Abu Nadr, the freedman of Umar bin Ubaydullah, from Abu Salama bin Abdul-Rahman, from Ayesha, and he related it as mentioned. Bukhari narrated it in Sawm (1969), and Muslim in Siyam (1156:175), both through the route of Malik with the same wording. In one version with Bukhari, "For he used to fast the whole of Shaban." And with Muslim, "He used to fast the whole of Shaban, he used to fast Shaban except for a little."Something similar was also narrated from Abu Hurairah. Abu Dawud narrated it (2435) from Musa bin Ismail, who said, Hammad related to us, from Muhammad bin Amr, from Abu Salama, from Abu Hurairah, from the Prophet ﷺ, with the same meaning, that is, the meaning of Ayesha's hadith, namely her statement, "The Messenger of Allah ﷺ used to fast until we would say he does not break his fast..." and he added, "He used to fast it except for a little, rather he used to fast all of it."Hammad here is Ibn Salama, whose memory changed toward the end of his life, so he erred in this and made it part of the musnad of Abu Hurairah. The correct view is that it belongs to the musnad of Ayesha or Umm Salama, as Nasai mentioned (4/150-151).Ahmad also narrated it (25101) from Yazid bin Harun, who said, Muhammad bin Amr related to us, from Abu Salama, who said, I asked Ayesha, "How did the Prophet ﷺ used to fast?" and she related the same. Tirmidhi also narrated it (737) from the hadith of Abdah, from Muhammad bin Amr with his chain, in abbreviated form.The agreement between Yazid bin Harun and Abdah, who is Ibn Sulayman Kullabi, a reliable and firmly established narrator among the men of the Jamaah, places the error with Hammad bin Salama.As for the meaning of his statement, "He used to fast it except for a little, rather he used to fast all of it," it means that he completed it once, and another time did not complete it, so it was said he fasts all of it, meaning he fasts in its beginning, its middle, and its end, not singling out any part of it nor covering it entirely with fasting. It has also been said that this is not to be taken at face value, and that what is meant is most of it, not all of it, and the word "all" is used to express what is predominant and most common. This was stated by Munziri.