“Fast when you sight it (the crescent), and break your fast when you sight it, and perform rites (nusuk of sacrifice) upon its sighting. If it is obscured from you, then complete thirty (days). And if two (trustworthy) witnesses testify, then fast and break your fast.”
Narrated by Aḥmad (18895) and al-Nasāʾī (2116) from the ḥadīth of a group of the Companions — may Allah be pleased with them.
Authenticated in Ṣaḥīḥ al-Jāmiʿ (3811) and Irwāʾ al-Ghalīl (909).
Brief Explanation of the Hadith
Allah, Exalted is He, has bestowed upon His servants countless blessings, and among the greatest of these is the blessing of the lunar crescents, which He has made as signs marking the times of acts of worship — such as fasting and breaking the fast, ḥajj and sacrificial rites, expiations, vows, and others.
In this ḥadīth, the Prophet — may Allah’s peace and blessings be upon him — directs his Companions to rely upon the actual sighting of the crescent moon for both fasting and breaking the fast. Thus, they are not to begin fasting Ramaḍān until the sighting of its crescent is confirmed on the night of the thirtieth of Shaʿbān, nor are they to end the fast until the sighting of the crescent of Shawwāl has been established.
His statement, “and perform the rites (nusuk) upon its sighting,” means: carry out the acts of worship that are linked to the sighting of the crescent — such as the sacrificial offerings and the rites of ḥajj in Dhū al-Ḥijjah — for these rites are not legislated except after the crescent has been sighted, since it is the sign of the month’s commencement.
The Prophet — may Allah’s peace and blessings be upon him — then clarified that if the crescent is obscured by clouds, dust, or anything similar, it becomes obligatory to complete the month as thirty days, whether in beginning the fast or ending it. This is from Allah’s mercy toward His servants, for He has not burdened them with what lies beyond their capacity.
The Prophet — may Allah’s peace and blessings be upon him — then moved on to clarify the means by which the sighting is to be established, saying: “If two witnesses testify, then fast and break your fast.” That is, the beginning and end of the month must be confirmed by the testimony of two witnesses, and these two must be upright and trustworthy (ʿadl), as established in the Sunnah. A sinful or unreliable person is not to be trusted with conveying matters of religious significance; therefore, the requirement of uprightness completes the meaning of the ḥadīth and fulfills the objective of the Sharīʿah in safeguarding the authenticity of religious rites.
The ḥadīth is explicit regarding the requirement of two witnesses to establish the sighting of the crescent. However, some scholars restricted this requirement to the sighting of the crescent of Shawwāl, whereas for the crescent of Ramaḍān the testimony of a single reliable witness suffices. This is in order to reconcile the present ḥadīth with the ḥadīth of Ibn ʿUmar — may Allah be pleased with them both — who said: “The people looked for the crescent, and I informed the Prophet — may Allah’s peace and blessings be upon him — that I had sighted it. So he fasted and ordered the people to fast.”
This indicates that a single trustworthy witness is sufficient for establishing the beginning of Ramaḍān, whereas the end of the month requires the testimony of two upright witnesses.
Thus, the ḥadīth serves as a foundational principle in the matter of crescent sighting and in regulating the acts of worship of the Muslims according to legal sighting, not astronomical calculation — as a mercy and ease for the Ummah.