الشمائل المحمدية

Humaid ibn Anas ibn Malik reported that he was asked about the fasting of the Prophet (Allah bless him and give him peace), so he said: "He used to fast during the month until we would assume that he did not intend to break fast during it, and he used to break fast until we would assume that he did not intend to fast during any of it. You would not wish to assume that he was performing the ritual prayer during the night, unless you saw him performing the ritual prayer, nor that he was sleeping, unless you saw him sleeping.”