I heard Allah's Messenger (ﷺ) saying, "When you see the crescent (of the month of Ramadan), start fasting, and when you see the crescent (of the month of Shawwal), stop fasting; and if the sky is overcast (and you can't see it) then regard the month of Ramadan as of 30 days."
The Command to Begin and End Fasting
This hadith establishes the fundamental principle for determining the commencement and conclusion of Ramadan fasting through visual moon sighting. The Prophet (ﷺ) explicitly linked the obligation to fast with the physical sighting of the Ramadan crescent, and the cessation of fasting with the sighting of the Shawwal crescent.
The Wisdom Behind Visual Sighting
Scholars explain that requiring actual moon sighting serves multiple purposes: it maintains the Prophetic tradition, involves the Muslim community in this important religious observance, and provides a clear, tangible method accessible to all people regardless of educational background.
This method also teaches reliance upon Allah's natural signs rather than complex calculations, fostering spiritual awareness of the Creator's signs in the universe.
The Ruling for Overcast Conditions
When clouds prevent moon sighting, the instruction to "regard the month of Ramadan as of 30 days" demonstrates the principle of completing the count when certainty cannot be achieved. This precautionary measure ensures we do not accidentally shorten the obligatory fasts of Ramadan.
Scholars emphasize that this completion applies specifically when the moon is not sighted due to weather conditions, not when the sky is clear and no sighting is reported.
Scholarly Consensus and Application
The majority of classical scholars held that moon sighting must be established through reliable visual testimony, not astronomical calculations. This hadith forms the basis for the unified practice of Muslim communities beginning and ending Ramadan together.
The ruling applies equally to both the beginning and end of Ramadan, creating consistency in religious practice across the Muslim ummah.