(13) باب ذِكْرِ الاِخْتِلاَفِ عَلَى مَنْصُورٍ فِي حَدِيثِ رِبْعِيٍّ فِيهِ
It was narrated that Ibn 'Abbas said:
"The Messenger of Allah said: "The Messenger of Allah said: Do not fast before Ramadan. Fast when you see it and stop fasting when you see it, and if clouds prevent you from seeing it, then complete Thirty (Days)."'
Reference: Sunan an-Nasa'i 2130
In-book reference: Book 22, Hadith 41
English translation: Vol. 3, Book 22, Hadith 2132