Sahih Bukhari :: Book# 31 :: Hadith# 115
Narrated Talha bin ‘Ubaid-Ullah: A bedouin with unkempt hair came to Allah’s Apostle and said, “O Allah’s Apostle! 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 Apostle 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 Apostle said, “If he is saying the truth, he will succeed (or he will be granted Paradise).”
Narrated Abu Huraira: Allah’s Apostle 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 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.”
Narrated Sahl: The Prophet 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.”
Narrated Abu Huraira: Allah’s Apostle 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.”
Narrated Ibn Umar: I heard Allah’s Apostle 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 crescent (month) of Ramadan (as of 30 days)”.
Narrated Abu Huraira: The Prophet 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.”