Surah Al-Baqarah (The Cow), Verse 185

شَهْرُ رَمَضَانَ الَّذِیْۤ اُنْزِلَ فِیْهِ الْقُرْاٰنُ هُدًی لِّلنَّاسِ وَبَیِّنٰتٍ مِّنَ الْهُدٰی وَالْفُرْقَانِ فَمَنْ شَهِدَ مِنْكُمُ الشَّهْرَ فَلْیَصُمْهُ وَمَنْ كَانَ مَرِیْضًا اَوْ عَلٰی سَفَرٍ فَعِدَّةٌ مِّنْ اَیَّامٍ اُخَرَ یُرِیْدُ اللّٰهُ بِكُمُ الْیُسْرَ وَلَا یُرِیْدُ بِكُمُ الْعُسْرَ وَلِتُكْمِلُوا الْعِدَّةَ وَلِتُكَبِّرُوا اللّٰهَ عَلٰی مَا هَدٰىكُمْ وَلَعَلَّكُمْ تَشْكُرُوْنَ ۟

Shahru Ramadaanallazeee unzila feehil Qur'aanu hudal linnaasi wa baiyinaatim minal hudaa wal furqaan; faman shahida minkumush shahra falyasumhu wa man kaana mareedan aw 'alaa safarin fa'iddatum min ayyaamin ukhar; yureedul laahu bikumul yusra wa laa yureedu bikumul 'usra wa litukmilul 'iddata wa litukabbirul laaha 'alaa maa hadaakum wa la'allakum tashkuroon

“Ramadhan is the (month) in which was sent down the Qur'an, as a guide to mankind, also clear (Signs) for guidance and judgment (Between right and wrong). So every one of you who is present (at his home) during that month should spend it in fasting, but if any one is ill, or on a journey, the prescribed period (Should be made up) by days later. Allah intends every facility for you; He does not want to put to difficulties. (He wants you) to complete the prescribed period, and to glorify Him in that He has guided you; and perchance ye shall be grateful.”

Quran 2:185 (Yusuf Ali Translation)