2dPoint

"O Believers, the Fast has been made obligatory on you just as it was prescribed for the followers of the Prophets before you. It is expected that this will produce piety in you...Ramadhan is the month in which the Quran was sent down; this Book is a perfect guidance for mankind and consits of clear teachings which show the right way and are a criterion of Truth and falsehood...
al-Baqarah: 183 & 185

Other related verses:
al-Baqarah: 184, 196
an-Nisa': 92
al-Maidah: 89,96
Maryam: 26
al-Ahzab: 35
al-Mujadalah: 4