The Prophet (ﷺ) said: Do not fast one day or two days just before Ramadan except in the case of a man who has been in the habit or observing a fast (on that day); and do not fast until you sight it (the moon). Then fast until you sight it. If a cloud appears on that day (i.e. 29th of Ramadan) then complete the number thirty (days) and then end the fasting: a month consists of twenty-nine days.
Hadith Text & Context
The Prophet (ﷺ) said: Do not fast one day or two days just before Ramadan except in the case of a man who has been in the habit of observing a fast (on that day); and do not fast until you sight it (the moon). Then fast until you sight it. If a cloud appears on that day (i.e. 29th of Ramadan) then complete the number thirty (days) and then end the fasting: a month consists of twenty-nine days.
This noble hadith from Sunan Abi Dawud 2327 contains essential rulings regarding the commencement and conclusion of Ramadan fasting, establishing clear boundaries to preserve the sanctity of the blessed month.
Prohibition of Pre-Ramadan Fasting
The prohibition against fasting one or two days before Ramadan serves to distinguish voluntary fasts from the obligatory fasts of Ramadan. This prevents confusion and maintains the distinct nature of Ramadan's worship.
The exception for one who regularly fasts on specific days (like Mondays and Thursdays) shows the Shari'ah's wisdom in preserving established acts of worship while preventing innovation.
Moon Sighting Principles
The command "do not fast until you sight it" establishes visual moon sighting as the primary method for determining Ramadan's beginning. This emphasizes tangible certainty over astronomical calculations in matters of worship.
The instruction to "fast until you sight it" for ending Ramadan maintains consistency in methodology, treating both commencement and conclusion with equal importance.
Completion of Thirty Days
When clouds obscure vision on the 29th day, completing thirty days ensures certainty in fulfilling the Ramadan obligation. This precautionary principle safeguards the completeness of worship.
The final statement "a month consists of twenty-nine days" acknowledges the natural lunar cycle while establishing the maximum completion period, balancing between the natural and the certain.
Scholarly Insights
Imam Nawawi explains that this hadith demonstrates the importance of distinguishing between voluntary and obligatory acts, preventing potential confusion in religious practice.
Ibn Hajar al-Asqalani emphasizes that the exception for habitual fasting shows the Shari'ah's consideration for established worship patterns while maintaining clear boundaries.
Contemporary scholars note that the principles established in this hadith form the foundation for modern moon sighting discussions and the calculation of Islamic months.