30/11. Chapter:
"Start observing Saum on seeing the crescent of Ramadan, and stop on seeing the crescent (of Shawwal)."
And ‘Ammar said, “Whoever observes Saum (fasting) on a doubtful day is disobeying Abul-Qasim (i.e., the Prophet ﷺ).”
Sahih Bukhari : 1908
Sahih BukhariHadith Number 1908
حَدَّثَنَا أَبُو الْوَلِيدِ، حَدَّثَنَا شُعْبَةُ، عَنْ جَبَلَةَ بْنِ سُحَيْمٍ، قَالَ سَمِعْتُ ابْنَ عُمَرَ ـ رضى الله عنهما ـ يَقُولُ قَالَ النَّبِيُّ صلى الله عليه وسلم " الشَّهْرُ هَكَذَا وَهَكَذَا ". وَخَنَسَ الإِبْهَامَ فِي الثَّالِثَةِ.
Narrated Ibn `Umar: The Prophet (ﷺ) said, "The month is like this and this," (at the same time he showed the fingers of both his hands thrice) and left out one thumb on the third time.
Reference : Sahih al-Bukhari 1908In-book reference : Book 30, Hadith 18USC-MSA web (English) reference : Vol. 3, Book 31, Hadith 132
