In the Qur'an, fasting (ṣawm / ṣiyām) is prescribed in Ramadan and its aim is taqwā (God-consciousness).
Elements in the Qur'an
- Prescribed, and why: "Fasting is prescribed for you as it was for those before you, so that you may attain taqwā." (2:183)
- Time — Ramadan: "The month of Ramadan in which the Qur'an was sent down… whoever of you witnesses the month, let him fast it." (2:185)
- The day's limits: "Eat and drink until the white thread of dawn becomes distinct from the black thread; then complete the fast until night." (2:187) — i.e. from dawn to nightfall (see Prayer times and astronomy).
- Ease: the sick and the traveller make up the days later; "God wills ease for you, not hardship." (2:185) For those unable, a fidya (2:184).
- Expiatory fasts: for a broken oath (5:89), ẓihār (58:3-4), manslaughter (4:92) and within Hajj (2:196).
- A different fast: Maryam's vow of silence (19:26).
An honest limit
The Qur'an gives the time, purpose and exemptions of fasting. Tarāwīḥ, the etiquette of suḥūr/ifṭār, and fixing Ramadan by the crescent moon are matters of the Sunnah and practice; the Qur'an gives no numeric rule for them.
Source: Qur'anic verses (M. Okuyan meal).