A bedouin with unkempt hair came to Allah's Messenger (ﷺ) and said, "O Allah's Messenger (ﷺ)! Inform me what Allah has made compulsory for me as regards the prayers." He replied: "You have to offer perfectly the five compulsory prayers in a day and night (24 hours), unless you want to pray Nawafil." The bedouin further asked, "Inform me what Allah has made compulsory for me as regards fasting." He replied, "You have to fast during the whole month of Ramadan, unless you want to fast more as Nawafil." The bedouin further asked, "Tell me how much Zakat Allah has enjoined on me." Thus, Allah's Messenger (ﷺ) informed him about all the rules (i.e. fundamentals) of Islam. The bedouin then said, "By Him Who has honored you, I will neither perform any Nawafil nor will I decrease what Allah has enjoined on me. Allah's Messenger (ﷺ) said, "If he is saying the truth, he will succeed (or he will be granted Paradise).

The Prophet (ﷺ) observed the fast on the 10th of Muharram ('Ashura), and ordered (Muslims) to fast on that day, but when the fasting of the month of Ramadan was prescribed, the fasting of the 'Ashura' was abandoned. `Abdullah did not use to fast on that day unless it coincided with his routine fasting by chance.

(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."

Allah's Messenger (ﷺ) said, "Fasting is a shield (or a screen or a shelter). So, the person observing fasting should avoid sexual relation with his wife and should not behave foolishly and impudently, and if somebody fights with him or abuses him, he should tell him twice, 'I am fasting." The Prophet (ﷺ) added, "By Him in Whose Hands my soul is, the smell coming out from the mouth of a fasting person is better in the sight of Allah than the smell of musk. (Allah says about the fasting person), 'He has left his food, drink and desires for My sake. The fast is for Me. So I will reward (the fasting person) for it and the reward of good deeds is multiplied ten times."

`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.

The Prophet (ﷺ) said, "There is a gate in Paradise called Ar-Raiyan, and those who observe fasts will enter through it on the Day of Resurrection and none except them will enter through it. It will be said, 'Where are those who used to observe fasts?' They will get up, and none except them will enter through it. After their entry the gate will be closed and nobody will enter through it."

Allah's Messenger (ﷺ) said, "Whoever gives two kinds (of things or property) in charity for Allah's Cause, will be called from the gates of Paradise and will be addressed, 'O slaves of Allah! Here is prosperity.' So, whoever was amongst the people who used to offer their prayers, will be called from the gate of the prayer; and whoever was amongst the people who used to participate in Jihad, will be called from the gate of Jihad; and whoever was amongst those who used to observe fasts, will be called from the gate of Ar-Raiyan; whoever was amongst those who used to give in charity, will be called from the gate of charity." Abu Bakr said, "Let my parents be sacrificed for you, O Allah's Messenger (ﷺ)! No distress or need will befall him who will be called from those gates. Will there be any one who will be called from all these gates?" The Prophet (ﷺ) replied, "Yes, and I hope you will be one of them."

Allah's Messenger (ﷺ) said, "When Ramadan begins, the gates of Paradise are opened."

Allah's Messenger (ﷺ) said, "When the month of Ramadan starts, the gates of the heaven are opened and the gates of Hell are closed and the devils are chained."

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 established prayers on the night of Qadr out of sincere faith and hoping for a reward from Allah, then all his previous sins will be forgiven; and whoever fasts in the month of Ramadan out of sincere faith, and hoping for a reward from Allah, then all his previous sins will be forgiven."

The Prophet (ﷺ) was the most generous amongst the people, and he used to be more so in the month of Ramadan when Gabriel visited him, and Gabriel used to meet him on every night of Ramadan till the end of the month. The Prophet (ﷺ) used to recite the Holy Qur'an to Gabriel, and when Gabriel met him, he used to be more generous than a fast wind (which causes rain and welfare).

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) said, "Allah said, 'All the deeds of Adam's sons (people) are for them, except fasting which is for Me, and I will give the reward for it.' Fasting is a shield or protection from the fire and from committing sins. If one of you is fasting, he should avoid sexual relation with his wife and quarreling, and if somebody should fight or quarrel with him, he should say, 'I am fasting.' By Him in Whose Hands my soul is' The unpleasant smell coming out from the mouth of a fasting person is better in the sight of Allah than the smell of musk. There are two pleasures for the fasting person, one at the time of breaking his fast, and the other at the time when he will meet his Lord; then he will be pleased because of his fasting."

While I was walking with `Abdullah he said, "We were in the company of the Prophet (ﷺ) and he said, 'He who can afford to marry should marry, because it will help him refrain from looking at other women, and save his private parts from committing illegal sexual relation; and he who cannot afford to marry is advised to fast, as fasting will diminish his sexual power."

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).

Allah's Messenger (ﷺ) said, "The month (can be) 29 nights (i.e. days), and do not fast till you see the moon, and if the sky is overcast, then complete Sha'ban as thirty days."

The Prophet (ﷺ) said, "The month is like this and this," (at the same time he showed the fingers of both his hands thrice) and left out one thumb on the third time.

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."