Umm Fadl bint Harith sent him to Muawiya in Sham. He said, "I arrived in Sham and completed her errand, and Ramadan began while I was still there. I sighted the crescent moon on the night of Friday, then returned to Madinah at the end of the month."Abdullah bin Abbas questioned me, and then mentioned the crescent moon and asked, "When did you sight the crescent?"I replied, "We saw it on the night of Friday."He asked, "You saw it yourself?"I said, "Yes, and the people saw it too, and they fasted, and Muawiya fasted."He said, "But we saw it on the night of Saturday, so we will continue fasting until we complete thirty days or sight it ourselves."I asked, "Is the sighting of Muawiya and his fasting not enough for you?"He replied, "No. This is how the Messenger of Allah ﷺ commanded us."
أن أم الفضل بنت الحارث بعثته إلى معاوية بالشام. قال: فقدمت الشام، فقضيت حاجتها، واستهل علي رمضان وأنا بالشام. فرأيت الهلال ليلة الجمعة، ثم قدمت المدينة في آخر الشهر، فسألني عبد الله بن عباس رضي الله عنهما، ثم ذكر الهلال فقال: متى رأيتم الهلال؟ فقلت: رأيناه ليلة الجمعة. فقال: أنت رأيته؟ فقلت: نعم، ورآه الناس وصاموا وصام معاوية. فقال: لكنا رأيناه ليلة السبت، فلا نزال نصوم حتى نكمل ثلاثين أو نراه. فقلت: أو لا تكتفي برؤية معاوية وصيامه؟ فقال: لا، هكذا أمرنا رسول الله ﷺ.
Muslim narrated it in the Book of Fasting (1087) via Ismail bin Jafar, from Muhammad bin Abu Harmala, from Kurayb, and so on as mentioned. His saying, "This is how the Messenger of Allah ﷺ commanded us," refers to his statement, "Fast upon sighting it and break the fast upon sighting it." He may have had another hadith more specific than this regarding such an occurrence. Ibn Abbas perhaps understood from this text that each city has its own sighting, due to the difference in the times the moon becomes visible in different locations, and this is the view held by some scholars.Others held that if the people of one city see the crescent moon, fasting becomes obligatory for all other cities as well. This is the position of Ahmad, Layth, and some of the companions of Shafii, as mentioned in Al-Mughni by Ibn Qudama, and it is also the position of the Malikis.The Permanent Committee for Scholarly Research and Ifta issued a fatwa (319) stating, "Whoever does not see the crescent moon at their location, whether the sky is clear or overcast, must complete the count as thirty days, if no one else saw it at a different location. But if the sighting of the crescent moon is established for them at a different location, they must follow whatever the general Muslim ruler of their country decides regarding fasting or breaking the fast, because his ruling on such a matter resolves the disagreement among the jurists over whether to take into account the difference in sighting locations or not. If the ruler governing their country is not Muslim, they should act according to what the council of the Islamic center in their country decides, whether to fast in accordance with a sighting of the crescent moon at a different location, or to break the fast, acting on the basis of taking into account the difference in sighting locations."The committee also said, "Each of the two groups may cite the very same text in support of their position, as they both cite as evidence His saying, "So whoever among you witnesses the month, let him fast it" [Baqarah 2:185], and His saying ﷺ, "They ask you about the crescent moons. Say, they are markers of time for the people" [Baqarah 2:189], and his saying ﷺ, 'Fast upon sighting it and break the fast upon sighting it,' and so on, along with other texts. This is because the two groups differ in their understanding of the texts and each follows its own approach in deriving evidence from them. This disagreement between them has had no ill effect to be feared, given the good intentions of both sides and each scholar's respect for the independent reasoning of the other. The earlier jurists among the imams also differed on this matter, and each had his own evidence."