Abu Huraira related that the Prophet (peace and blessings be upon him) said: Whoever fasts during Ramadan with faith and seeking his reward from Allah will have his past sins forgiven. Whoever prays during the nights in Ramadan with faith and seeking his reward from Allah will have his past sins forgiven. And he who passes Lailat al-Qadr in prayer with faith and seeking his reward from Allah will have his past sins forgiven (Bukhari, Muslim).
THE QURAN ON FASTING
"O you who believe! Fasting is prescribed for you as it was prescribed for those before you, that you may become Al-Muttaqun (the pious).
(Fasting) for a fixed number of days, but if any of you is ill or on a journey, the same number (should be made up) from other days. And as for those who can fast with difficulty, (i.e. an old man, etc.), they have (a choice either to fast or) to feed a poor person (for every day). But whoever does good of his own accord, it is better for him. And that you fast, it is better for you if only you know." (2:183-84)
"The month of Ramadan in which was revealed the Quran, a guidance for mankind and clear proofs for the guidance and the criterion (between right and wrong). So whoever of you sights (the crescent on the first night of) the month (of Ramadan), he must fast that month, and whoever is ill or on a journey, the same number (of days which one did not fast must be made up) from other days.
