Abu Da'ud أبو داود السجستاني الأزدي · The Book of Fasting

'I fasted Ramadan' or 'I prayed Qiyam throughout the whole month."' I do not know whether he dislike self-praise or he said: "Inevitably there will be heedlessness and sleep." (Da 'if)

"Jibril, peace be upon him, came to me and said: 'The month is twenty-nine days."'

"The Messenger of Allah used to join Shaban to Ramadan." '

the Messenger of Allah used to encourage the people to pray Qiyam in Ramadan, without insisting on that. He said: "Whoever spends the nights of Ramadan in prayer out of faith and in the hope of reward, he will be forgiven his previous sins." '

"Should a menstruating woman make up the prayers when she becomes pure?" she said: "Are youa Haruri? We used to menstruate at the time of the Messenger of Allah then we would become pure. He told us to make up the fast, but he did not tell us to make up the prayers."

"I said: 'O Messenger of Allah, sometimes you fast, and you hardly ever break your hardly ever fast, except two days which, if you are fasting, you include them in your fast, and if you are not fasting, then you fast them on your own.' He said: 'Which two days?' I said: 'Monday and Thursday.' He said: 'Those are two days in which deeds are shown to the Lord of the worlds, and I like my deeds to be shown…

"someone who heard him told me that Ibn 'Umar (said) that the Prophet said: 'Whoever fasts every day of his life, then he has not fasted."