Surah Al-Baqarah [2:185]
During the month of Ramadan the Qur ‘an was sent down as a guidance to the people with Clear Signs of the true guidance and as the Criterion (between right and wrong).

So those of you who live to see that month should fast it, and whoever is sick or on a journey should fast the same number of other days instead.
Allah wants ease and not hardship for you so that you may complete the number of days required, magnify Allah for what He has guided you to, and give thanks to Him.