What did the Prophet Muhammad (peace be upon him) say about the fasting of David?
 Narrated `Abdullah bin `Amr bin Al-`As:                     "Once Allah's Apostle came to me," and then he narrated the whole narration, i.e. your guest has a right on you, and your wife has a right on you. I then asked about the fasting of David. The Prophet replied, "Half of the year," (i.e. he used to fast on every alternate day).