Al-Baqarah 2:185 شهر رمضان الذي انزل فيه القران هدى للناس وبينات من الهدى والفرقان فمن شهد منكم الشهر فليصمه ومن كان مريضا او على سفر فعدة من ايام اخر يريد الله بكم اليسر ولا يريد بكم العسر ولتكملوا العدة ولتكبروا الله على ما هداكم ولعلكم تشكرون ١٨٥

It was in the month of Ramadan that the Quran was revealed as guidance for mankind, clear messages giving guidance and distinguishing between right and wrong. So any one of you who is present that month should fast, and anyone who is ill or on a journey should make up for the lost days by fasting on other days later. God wants ease for you, not hardship. He wants you to complete the prescribed period and to glorify Him for having guided you, so that you may be thankful.