(The tribe of) Quraish used to fast on the day of Ashura' in the Pre-Islamic period, and then Allah's Apostle ordered (Muslims) to fast on it till the fasting in the month of Ramadan was prescribed; whereupon the Prophet (ﷺ) said, "He who wants to fast (on 'Ashura') may fast, and he who does not want to fast may not fast."

`Umar asked the people, "Who remembers the narration of the Prophet (ﷺ) about the affliction?" Hudhaifa said, "I heard the Prophet (ﷺ) saying, 'The affliction of a person in his property, family and neighbors is expiated by his prayers, fasting, and giving in charity." `Umar said, "I do not ask about that, but I ask about those afflictions which will spread like the waves of the sea." Hudhaifa replied, "There is a closed gate in front of those afflictions." `Umar asked, "Will that gate be opened or broken?" He replied, "It will be broken." `Umar said, "Then the gate will not be closed again till the Day of Resurrection." We said to Masruq, "Would you ask Hudhaifa whether `Umar knew what that gate symbolized?" He asked him and he replied "He (`Umar) knew it as one knows that there will be night before tomorrow, morning.

I heard Allah's Messenger (ﷺ) saying, "When you see the crescent (of the month of Ramadan), start fasting, and when you see the crescent (of the month of Shawwal), stop fasting; and if the sky is overcast (and you can't see it) then regard the month of Ramadan as of 30 days."

The Prophet (ﷺ) said, "Whoever does not give up forged speech and evil actions, Allah is not in need of his leaving his food and drink (i.e. Allah will not accept his fasting.)"

Allah's Messenger (ﷺ) mentioned Ramadan and said, "Do not fast unless you see the crescent (of Ramadan), and do not give up fasting till you see the crescent (of Shawwal), but if the sky is overcast (if you cannot see it), then act on estimation (i.e. count Sha'ban as 30 days).

The Prophet (ﷺ) or Abul-Qasim said, "Start fasting on seeing the crescent (of Ramadan), and give up fasting on seeing the crescent (of Shawwal), and if the sky is overcast (and you cannot see it), complete thirty days of Sha'ban."

The Prophet (ﷺ) said, "The two months of `Id i.e. Ramadan and Dhul-Hijja, do not decrease (in superiority).

It was the custom among the companions of Muhammad that if any of them was fasting and the food was presented (for breaking his fast), but he slept before eating, he would not eat that night and the following day till sunset. Qais bin Sirma-al-Ansari was fasting and came to his wife at the time of Iftar (breaking one's fast) and asked her whether she had anything to eat. She replied, "No, but I would go and bring some for you." He used to do hard work during the day, so he was overwhelmed by sleep and slept. When his wife came and saw him, she said, "Disappointment for you." When it was midday on the following day, he fainted and the Prophet (ﷺ) was informed about the whole matter and the following verses were revealed: "You are permitted To go to your wives (for sexual relation) At the night of fasting." So, they were overjoyed by it. And then Allah also revealed: "And eat and drink Until the white thread Of dawn appears to you Distinct from the black thread (of the night)." (2.187)

Zaid bin Thabit said, "We took the Suhur with the Prophet (ﷺ) . Then he stood for the prayer." I asked, "What was the interval between the Suhur and the Adhan?" He replied, "The interval was sufficient to recite fifty verses of the Qur'an."

The Prophet (ﷺ) fasted for days continuously; the people also did the same but it was difficult for them. So, the Prophet (ﷺ) forbade them (to fast continuously for more than one day). They slid, "But you fast without break (no food was taken in the evening or in the morning)." The Prophet (ﷺ) replied, "I am not like you, for I am provided with food and drink (by Allah).

The Prophet (ﷺ) said, "Take Suhur as there is a blessing in it."

The Prophet (ﷺ) was cupped while he was fasting.

Anas bin Malik was asked whether they disliked the cupping for a fasting person. He replied in the negative and said, "Only if it causes weakness."

We set out with Allah's Messenger (ﷺ) on one of his journeys on a very hot day, and it was so hot that one had to put his hand over his head because of the severity of heat. None of us was fasting except the Prophet and Ibn Rawaha.

Sometimes I missed some days of Ramadan, but could not fast in lieu of them except in the month of Sha'ban." Said Yahya, a sub-narrator, "She used to be busy serving the Prophet (ﷺ) ."

We were in the company of the Prophet (ﷺ) on a journey and he was fasting, and when the sun set, he addressed somebody, "O so-and-so, get up and mix Sawiq with water for us." He replied, "O Allah's Apostle! (Will you wait) till it is evening?" The Prophet (ﷺ) said, "Get down and mix Sawiq with water for us." He replied, "O Allah's Messenger (ﷺ)! (If you wait) till it is evening." The Prophet (ﷺ) said again, "Get down and mix Sawiq with water for us." He replied, "It is still daytime."(1) The Prophet (ﷺ) said again, "Get down and mix Sawiq with water for us." He got down and mixed Sawiq for them. The Prophet (ﷺ) drank it and then said, "When you see night falling from this side, the fasting person should break his fast."

Asma bint Abi Bakr said, "We broke our fast during the lifetime of the Prophet (ﷺ) on a cloudy day and then the sun appeared." Hisham was asked, "Were they ordered to fast in lieu of that day?" He replied, "It had to be made up for." Ma`mar said, "I heard Hisham saying, "I don't know whether they fasted in lieu of that day or not."

"The Prophet (ﷺ) sent a messenger to the village of the Ansar in the morning of the day of 'Ashura' (10th of Muharram) to announce: 'Whoever has eaten something should not eat but complete the fast, and whoever is observing the fast should complete it.' "She further said, "Since then we used to fast on that day regularly and also make our boys fast. We used to make toys of wool for the boys and if anyone of them cried for, he was given those toys till it was the time of the breaking of the fast."

Allah's Messenger (ﷺ) said, "Do not fast continuously day and night (practice Al-Wisal) and if anyone of you intends to fast continuously day and night, he should continue till the Suhur time." They said, "But you practice Al-Wisal, O Allah's Messenger (ﷺ)!" The Prophet (ﷺ) said, "I am not similar to you;. during my sleep I have One Who makes me eat and drink."

The Prophet (ﷺ) never fasted in any month more than in the month of Sha'ban. He used to say, "Do those deeds which you can do easily, as Allah will not get tired (of giving rewards) till you get bored and tired (of performing religious deeds)." The most beloved prayer to the Prophet (ﷺ) was the one that was done regularly (throughout the life) even if it were little. And whenever the Prophet (ﷺ) offered a prayer he used to offer it regularly .