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 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."

Narrated Ibn `Abbas: The Prophet 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 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).

Narrated Abu Huraira: The Prophet 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.)"

Narrated Abu Huraira: Allah's Apostle 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."

Narrated 'Alqama: While I was walking with `Abdullah he said, "We were in the company of the Prophet 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."

Narrated `Abdullah bin `Umar: Allah's Apostle 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).