Fasting is one of the five pillars of Islam. At the same time, it is one of the great signs of Islam. It was made fard (obligatory) in Madinah, one and a half year after the Hegira (Migration from Makkah to Madinah) and on the 10th day of the month of Shaban. Its obligation is established by the Book (the Qur'an), the Sunnah (the practice of the Prophet) and by Ijma' (consensus of the ummah/community or the ulama/scholars of Islam).

In the Qur'an, the following is stated:

O you who believe! Prescribed for you is the Fast, as it was prescribed for those before you...” (The Qur'an, Al-Baqarah, 2:183)