Sahih al-Bukhari

Allah's Messenger (ﷺ) used to leave fasting in a certain month till we thought that he would not fast in that month, and he used to fast in another month till we thought he would not stop fasting at all in that month. And if one wanted to see him praying at night, one could see him (in that condition), and if one wanted to see him sleeping at night, one could see him (in that condition) too.

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)."

"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).

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).

Allah's Messenger (ﷺ) was informed that I had taken an oath to fast daily and to pray (every night) all the night throughout my life (so Allah's Messenger (ﷺ) came to me and asked whether it was correct): I replied, "Let my parents be sacrificed for you! I said so." The Prophet (ﷺ) said, "You can not do that. So, fast for few days and give it up for few days, offer Salat (prayer) and sleep. Fast three days a month as the reward of good deeds is multiplied ten times and that will be equal to one year of fasting." The Prophet (ﷺ) said to me, "Fast one day and give up fasting for two days." I replied, "I can do better than that." The Prophet (ﷺ) said to me, "Fast one day and give up fasting for a day and that is the fasting of Prophet David and that is the best fasting." I said, "I have the power to fast better (more) than that." The Prophet (ﷺ) said, "There is no better fasting than that."

The news of my daily fasting and praying every night throughout the night reached the Prophet. So he sent for me or I met him, and he said, "I have been informed that you fast everyday and pray every night (all the night). Fast (for some days) and give up fasting (for some days); pray and sleep, for your eyes have a right on you, and your body and your family (i.e. wife) have a right on you." I replied, "I have more power than that (fasting)." The Prophet (ﷺ) said, "Then fast like the fasts of (the Prophet) David". I said, "How?" He replied, "He used to fast on alternate days, and he used not to flee on meeting the enemy." I said, "From where can I get that chance?" (`Ata' said, "I do not know how the expression of fasting daily throughout the life occurred.") So, the Prophet (ﷺ) said, twice, "Whoever fasts daily throughout his life is just as the one who does not fast at all."

The Prophet (ﷺ) said (to `Abdullah), "Fast three days a month." `Abdullah said, (to the Prophet) "I am able to fast more than that." They kept on arguing on this matter till the Prophet (ﷺ) said, "Fast on alternate days, and recite the whole Qur'an once a month." `Abdullah said, "I can recite more (in a month)," and the argument went on till the Prophet (ﷺ) said, "Recite the Qur'an once each three days." (i.e. you must not recite the whole Qur'an in less than three days).

The Prophet (ﷺ) said to me, "You fast daily all the year and pray every night all the night?" I replied in the affirmative. The Prophet (ﷺ) said, "If you keep on doing this, your eyes will become weak and your body will get tired. He who fasts all the year is as he who did not fast at all. The fasting of three days (a month) will be equal to the fasting of the whole year." I replied, "I have the power for more than this." The Prophet (ﷺ) said, "Then fast like the fasting of David who used to fast on alternate days and would never flee from the battle field, on meeting the enemy."

Allah's Messenger (ﷺ) was informed about my fasts, and he came to me and I spread for him a leather cushion stuffed with palm fires, but he sat on the ground and the cushion remained between me and him, and then he said, "Isn't it sufficient for you to fast three days a month?" I replied, "O Allah's Apostle! (I can fast more)." He said, "Five?" I replied, "O Allah's Messenger (ﷺ)! (I can fast more)." He said, "Seven?" I replied, "O Allah's Messenger (ﷺ)! (I can fast more)." He said, "Nine (days per month)?" I replied, "O Allah's Messenger (ﷺ)! (I can fast more)" He said, "Eleven (days per month)?" And then the Prophet said, "There is no fast superior to that of the Prophet (ﷺ) David it was for half of the year. So, fast on alternate days."

My friend (the Prophet (ﷺ) ) advised me to observe three things: (1) to fast three days a month; (2) to pray two rak`at of Duha prayer (forenoon prayer); and (3) to pray witr before sleeping.

The Prophet (ﷺ) paid a visit to Um-Sulaim and she placed before him dates and ghee. The Prophet (ﷺ) said, "Replace the ghee and dates in their respective containers for I am fasting." Then he stood somewhere in her house and offered an optional prayer and then he invoked good on Um-Sulaim and her family. Then Um-Sulaim said, "O Allah's Messenger (ﷺ)! I have a special request (today)." He said, "What is it?" She replied, "(Please invoke for) your servant Anas." So Allah's Messenger (ﷺ) did not leave anything good in the world or the Hereafter which he did not invoke (Allah to bestow) on me and said, "O Allah! Give him (i.e. Anas) property and children and bless him." Thus I am one of the richest among the Ansar and my daughter Umaina told me that when Al-Hajjaj came to Basra, more than 120 of my offspring had been buried.

That the Prophet (ﷺ) asked him (Imran) or asked a man and `Imran was listening, "O Abu so-and-so! Have you fasted the last days of this month?" (The narrator thought that he said, "the month of Ramadan"). The man replied, "No, O Allah's Messenger (ﷺ)!" The Prophet (ﷺ) said to him, "When you finish your fasting (of Ramadan) fast two days (in Shawwal)." Through another series of narrators `Imran said, "The Prophet (ﷺ) said, '(Have you fasted) the last days of Sha'ban?"

I asked Jabir "Did the Prophet (ﷺ) forbid fasting on Fridays?" He replied, "Yes." (Other narrators added, "If he intends to fast only that day.")

I heard the Prophet (ﷺ) saying, "None of you should fast on Friday unless he fasts a day before or after it."

The Prophet (ﷺ) visited her (Juwairiya) on a Friday and she was fasting. He asked her, "Did you fast yesterday?" She said, "No." He said, "Do you intend to fast tomorrow?" She said, "No." He said, "Then break your fast." Through another series of narrators, Abu Aiyub is reported to have said, "He ordered her and she broke her fast."

I asked `Aisha "Did Allah s Apostle, use to choose some special days (for fasting)?" She replied, "No, but he used to be regular (constant) (in his service of worshipping). Who amongst you can endure what Allah's Messenger (ﷺ) used to endure?"

"While the people were with me on the day of `Arafat they differed as to whether the Prophet (ﷺ) was fasting or not; some said that he was fasting while others said that he was not fasting. So, I sent to him a bowl full of milk while he was riding over his camel and he drank it."

The people doubted whether the Prophet (ﷺ) was fasting on the day of `Arafat or not, so I sent milk while he was standing at `Arafat, he drank it and the people were looking at him.

(the slave of Ibn Azhar) I witnessed the `Id with `Umar bin Al-Khattab who said, Allah's Messenger (ﷺ) has forbidden people to fast on the day on which you break fasting (the fasts of Ramadan) and the day on which you eat the meat of your sacrifices (the first day of `Id ul Fitr and `Id ul-Adha).

The Prophet (ﷺ) forbade the fasting of `Id-ul-Fitr and `Id-ul-Adha (two feast days) and also the wearing of As-Samma' (a single garment covering the whole body), and sitting with one's leg drawn up while being wrapped in one garment. He also forbade the prayers after the Fajr (morning) and the `Asr (afternoon) prayers.