"Once Allah's Messenger (ﷺ) 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 (ﷺ) replied, "Half of the year," (i.e. he used to fast on every alternate day).
Sahih al-Bukhari Book 30, Hadith 81
← Previous Hadith I asked Anas about the fasting of the Prophet. He said "Whenever I liked to see the Prophet (ﷺ) fasting in any month, I could see that, and whenever I liked to see him not fasting, I could see that too, and if I liked to see him praying in any night, I could see that, and if I liked to see him sleeping, I could see that, too." Anas further said, "I never touched silk or velvet softer than the hand of Allah's Messenger (ﷺ) and never smelled musk or perfumed smoke more pleasant than the smell of Allah's Messenger (ﷺ)."

Sahih al-Bukhari Book 30, Hadith 80 Next Hadith → Allah's Messenger (ﷺ) said to me, "O `Abdullah! Have I not been informed that you fast during the day and offer prayers all the night." `Abdullah replied, "Yes, O Allah's Messenger (ﷺ)!" The Prophet (ﷺ) said, "Don't do that; fast for few days and then give it up for few days, offer prayers and also sleep at night, as your body has a right on you, and your wife has a right on you, and your guest has a right on you. And it is sufficient for you to fast three days in a month, as the reward of a good deed is multiplied ten times, so it will be like fasting throughout the year." I insisted (on fasting) and so I was given a hard instruction. I said, "O Allah's Messenger (ﷺ)! I have power." The Prophet (ﷺ) said, "Fast like the fasting of the Prophet (ﷺ) David and do not fast more than that." I said, "How was the fasting of the Prophet (ﷺ) of Allah, David?" He said, "Half of the year," (i.e. he used to fast on every alternate day). Afterwards when `Abdullah became old, he used to say, "It would have been better for me if I had accepted the permission of the Prophet (which he gave me i.e. to fast only three days a month).

Sahih al-Bukhari Book 30, Hadith 82