“I intend to keep the fast of Ramadan which is compulsory. O Allah, accept my fast, for Thou are the Hearer, the Wise.”
This intention can be willed in the heart, but it is better to say it in words when one stands for the Fajr (morning) prayer. The intention recognises the obligatory nature of fasting during the month of Ramadan as prescribed in the Qur’an:
“O ye who believe, Fasting is prescribed for you as it was prescribed for those before you, that you may learn self-restraint” Surah 2 verse 183
Fasting is incumbent on every sane male and female Muslim over the age of puberty who are physically fit. The sick, insane, minors, travelers, women who are menstruating, breast feeding, bleeding after childbirth, or pregnant, and the very old need not fast. Except for the insane, all other exempt persons must make up for the days lost as soon as possible.
The Prophet (s.a.w.s): “If anyone breaks his fast one day in Ramadan without a concession granted to him by Allah, a perpetual fast will not atone for it.” AbuHurayrah