How can we reconcile the fasting of our master David (peace be upon him) with the fasting of the Prophet (peace be upon him), of whom it was reported that he used to fast and break his fast, and his fasting during the months of Muharram and Sha'ban?

The best voluntary fasting is the fast of Dawud (peace be upon him), which is to fast one day and break the fast the next. This is based on the Prophet's (peace and blessings be upon him) saying: "Fast one day and break fast the next; that is the fasting of Dawud (peace be upon him), and it is the best of fasting." It is superior to perpetual fasting because it is more difficult for the soul.

The fast of Dawud does not conflict with fasting on virtuous days like the Day of Arafah and Ashura. If a day of breaking fast in Dawud's fasting coincides with a day whose fasting is recommended, then it is better to fast it. This does not diminish the virtue of fasting one day and breaking fast the next.

The Prophet's (peace and blessings be upon him) frequent fasting in certain months, such as Sha'ban and Muharram, meant that he fasted most of the month, but not the entire month. This does not contradict the fact that he (peace and blessings be upon him) did not continuously observe the fast of Dawud, because the absolute superiority of Dawud's fast applies to others, not to him (peace and blessings be upon him).

If you desire what is best for you, then fast like Dawud.