(8) باب قَبُولِ شَهَادَةِ الرَّجُلِ الْوَاحِدِ عَلَى هِلاَلِ شَهْرِ رَمَضَانَ وَذِكْرِ الاِخْتِلاَفِ فِيهِ عَلَى سُفْيَانَ فِي حَدِيثِ سِمَاكٍ
It was narrated that:
'Abdur-Rahman bin Zaid bin Al-Khattab addressed the people on the day concerning which there was doubt (as to whether the month had begun) and said: "I sat with the Companions of the Messenger of Allah and asked them, and they a narrated that the Messenger of Allah said: 'Fast when you see it and stop fasting when you see it, and perform the rites on that basis. If it is obscured, then complete thirty days, and if two witnesses testify then fast and stop fasting."
Reference: Sunan an-Nasa'i 2116
In-book reference: Book 22, Hadith 27
English translation: Vol. 3, Book 22, Hadith 2118