Chapter: What Has Been Related About Fasting Three (Days) Of Every Month
Abu Hurairah narrated: The Messenger of Allah took a covenant from me for three: To not sleep except after performing Witr, to fast three days of every month, and to perform the Duha prayer.
Abu Dharr narrated that : the Messenger of Allah said: O Abu Dharr! When you fast three days out of a month, then fast the thirteenth, fourteenth, and fifteenth.
Abu Dharr narrated: The Messenger of Allah said: 'Whoever fasts three days in every month, then that is (similar to) fasting every day.' Then Allah Mighty and Sublime is He, attested to that in His Book, by revealing: Whoever brings a good deed, shall have ten times the like thereof. So a day is like ten.
Yazid Ar-Rishk said: I heard Mu'adhah saying to Aishah: 'Did the Messenger of Allah fast three days of every month?' She replied in the affirmative. So she said: 'Which of them would he fast?' She said: 'Which of them he would fast was not noticeable.'