The Prophet Muhammad (Sal-allahu-aleihi-wasallam) said, "Whoever fasted the month of Ramadan out of sincere Faith (i.e. belief) and hoping for a reward from Allah, then all his past sins will be forgiven."

Narrated by Abu Huraira (Radi Allah Ta'lah Anhu); Sahih Bukhari transmitted it. Hadith No.231 of Sahih Bukhari Vol 3 .

The Prophet Muhammad (Sal-allahu-aleihi-wasallam) 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."

The Prophet Muhammad (Sal-allahu-aleihi-wasallam) said, "Ramadan, a blessed month, has come to you during which Allah has made it obligatory for you to fast. In it the gates of Heaven are opened, the gates of al-Jahim are locked, and the rebellious devils are chained. In it Allah has a night which is better than a thousand months. He who is deprived of its good has indeed suffered deprivation."

The Prophet Muhammad (Sal-allahu-aleihi-wasallam) said, "Fasting and the Qur'an intercede for a man. Fasting says, 'O my Lord, I have kept him away from his food and his passions by day, so accept my intercession for him.' The Qur'an says, 'I have kept him away from sleep by night, so accept my intercession for him.' Then their intercession is accepted."

The Prophet Muhammad (Sal-allahu-aleihi-wasallam) said, "He who gives one who has been fasting something with which to break his fast, or who equips a fighter, will have a reward equivalent to his."

The Prophet Muhammad (Sal-allahu-aleihi-wasallam) 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.)"

The Prophet Muhammad (Sal-allahu-aleihi-wasallam) said, "Many a one who fasts obtains nothing from his fasting but thirst, and many a one who prays during the night obtains nothing from his night prayers but wakefulness."

The Prophet Muhammad (Sal-allahu-aleihi-wasallam) said, "Allah said: 'The Fast is for Me and I will give the reward for it, as he (the one who observes the fast) leaves his sexual desire, food and drink for My Sake. Fasting is a screen (from Hell) and there are two pleasures for a fasting person, one at the time of breaking his fast, and the other at the time when he will meet his Lord. And the smell of the mouth of a fasting person is better in Allah's Sight than the smell of musk"