Narrated Abu Huraira (RA):
The Prophet (PBUH) 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.)"
Source: Sahi Bukhari Volume 3, Book 31, Number 127
Abu Amama (RA) transmits that he heard Allah's messenger (SAW) stating:
"I was sleeping when two persons came near me. They held my arms and brought me on a steep hill and asked me to climb the rise. I said: I cannot climb it. They said: We will make it easier for you to climb. Thus I climbed it until I reached the top. There I heard shrieks and shouts. I asked them about the sound. They said these are the shrieks of the People of Hell. Again they proceeded further with me, where I saw some people hanging upside down and their mouths were torn open and were bleeding. I asked as to who were these people? They replied: Those are the people who broke the fast before the time."
Abu Huraira (R) related that the Prophet (S) said that Allah said:
"Every deed of a person will recieve 10-700 times reward except fasting, for it is for Me and i shall reward it as i like. There are two ways of joy for ones fasts: when you break the fast and when he will meet his Lord".
On the authority of Abu Harayrah (may Allah be pleased with him) from the Prophet who said: Allah says:
Fasting is Mine and it I who give reward for it. [A man] gives up his sexual passion, his food and his drink for my sake. Fasting is like a shield, and he who fasts has two joys: a joy whin he breaks his fast and a joy when he meets his Lord. The change in the breath of the mouth of him who fasts is better in Allah's estimation than the smell of musk.
Narrated Sahl bin Saad(RA):
The Prophet(SAW) said,
"There is a gate in Paradise called Ar-Rayyan, 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 you used to...