فإن رأوه صاموا
Translation: If they see it, they fast.
In raʾawhu, the pronoun refers to the crescent. Once the sighting is established through the prescribed means, the following day is observed as a Ramadan fast.
The plural ṣāmū sets out the general result; the later clauses distinguish a personal sighting from legally accepted testimony that establishes the month for the community.
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Kitab al-Sawm: Crescent Sighting and Establishing Ramadan
فإن رأوه صاموا
Translation: If they see it, they fast.
In raʾawhu, the pronoun refers to the crescent. Once the sighting is established through the prescribed means, the following day is observed as a Ramadan fast.
The plural ṣāmū sets out the general result; the later clauses distinguish a personal sighting from legally accepted testimony that establishes the month for the community.