Fasting in Sha’baan ‘Aa’ishah (may Allaah be pleased with her) said: “The Messenger (peace and blessings of Allaah be upon him) used to fast until we thought he would never break his fast, and not fast until we thought he would never fast. I never saw the Messenger of Allaah fasting for an entire month except in Ramadaan, and I never saw him fast more than he did in Sha’baan.” (Narrated by al-Bukhaari, no. 1833; Muslim, no. 1956).
According to a report narrated by Muslim (no. 1957), “He used to fast all of Sha’baan, he used to fast all but a little of Sha’baan.”
Usaamah ibn Zayd (may Allaah be pleased with them both) said: “I said, ‘O Messenger of Allaah, I do not see you fasting in any other month like you fast in Sha’baan.’ He said, ‘That is a month to which people do not pay attention, between Rajab and Ramadaan, and it is a month in which deeds are lifted up to the Lord of the Worlds. I like for my deeds to be lifted up when I am fasting.’” (Narrated by al-Nasaa’i, see Saheeh al-Targheeb wa’l-Tarheeb, page 425). According to a report narrated by Abu Dawood (no. 2076) she said: “The most beloved of months for the Messenger of Allaah (peace and blessings of Allaah be upon him) to fast in was Sha’baan, and his fasting in Sha’baan was continuous with his fasting in Ramadaan.” (Classed as saheeh by al-Albaani, see Saheeh Sunan Abi Dawood, 2/461)