Usamah bin Zaid said:
"I said: 'O Messenger of Allah (ﷺ), I do not see you fasting any month as much as Shaban.'
He (ﷺ) said: 'That is a month to which people do not pay much attention, between Rajab and Ramdhaan. It is a month in which the deeds are taken up to the Lord of the worlds, and I like that my deeds be taken up when I am fasting."'

Narrated: Abu Salamah
"I asked Aishah about the fasting of the Messenger of Allah (ﷺ) and she said: '
He (ﷺ) used to fast until we would say: "He (ﷺ) has fasted," and he (ﷺ) used not to fast until we would say: "He (ﷺ) is not fasting." And I never saw him (ﷺ) fast more in any month than he fasted in Shabaan. He (ﷺ) used to fast all of Shabaan, he used to fast all of Shaaban but a little."

It was narrated from Abu Salamah that Umm Salamah said:
"I never saw the Messenger of Allah (ﷺ) fast two consecutive months, but he used to join Shabaan to Ramdhaan." '