The Messenger of Allah ﷺ came in to see me and said, "Have I not been informed that you stand in prayer all night and fast all day?"I replied, "Yes."He said, "Do not do so. Stand in prayer and sleep, fast and break your fast. For your body has a right over you, your eye has a right over you, your guests have a right over you, and your wife has a right over you. You may well live a long life. It is enough for you to fast three days each month, for every good deed is rewarded tenfold, and that amounts to fasting all the time."But I pressed for more, and so more was imposed on me. I said, "I am able to do more than that."He said, "Then fast three days each week."I pressed again, and more was imposed on me. I said, "I am able to do more than that."He said, "Then fast as the Prophet of Allah Dawud fasted."I asked, "And what was the fast of the Prophet of Allah Dawud?"He replied, "Half of all time."
دخل علي رسول الله ﷺ فقال: ألم أخبر أنك تقوم الليل وتصوم النهار قلت: بلى، قال: فلا تفعل، قم ونم، وصم وأفطر، فإن لجسدك عليك حقا، وإن لعينك عليك حقا، وإن لزورك عليك حقا، وإن لزوجك عليك حقا، وإنك عسى أن يطول بك عمر، وإن من حسبك أن تصوم من كل شهر ثلاثة أيام، فإن بكل حسنة عشر أمثالها، فذلك الدهر كله قال: فشددت فشدد علي، فقلت: فإني أطيق غير ذلك، قال: فصم من كل جمعة ثلاثة أيام قال: فشددت فشدد علي، قلت: أطيق غير ذلك، قال: فصم صوم نبي الله داود قلت: وما صوم نبي الله داود؟ قال: نصف الدهر
Bukhari reported it in al-Adab (6134) from Ishaq bin Mansur, who said, Rawh bin Ubada narrated to us, who said, Husayn narrated to us, from Yahya bin Abu Kathir, from Abu Salama bin Abdul-Rahman, from Abdullah bin Amr, who said, and he mentioned it.Muslim reported it in al-Siyam (1159:183) from Zuhayr bin Harb, who said, Rawh bin Ubada narrated to us with the same chain, except that he did not mention its full wording, but rather mentioned what differed from the wording mentioned before it. Among what he said was, "and he did not say, your visitor has a right over you," but instead said, "and your child has a right over you." Muslim gave many chains and wordings for it, and many of them are mentioned in the Book of Fasting.