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 : 1907
Sahih BukhariHadith Number 1907
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، حَدَّثَنَا مَالِكٌ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ ـ رضى الله عنهما ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " الشَّهْرُ تِسْعٌ وَعِشْرُونَ لَيْلَةً، فَلاَ تَصُومُوا حَتَّى تَرَوْهُ، فَإِنْ غُمَّ عَلَيْكُمْ فَأَكْمِلُوا الْعِدَّةَ ثَلاَثِينَ ".
Narrated `Abdullah bin `Umar: Allah's Messenger (ﷺ) said, "The month (can be) 29 nights (i.e. days), and do not fast till you see the moon, and if the sky is overcast, then complete Sha'ban as thirty days."
Reference : Sahih al-Bukhari 1907In-book reference : Book 30, Hadith 17USC-MSA web (English) reference : Vol. 3, Book 31, Hadith 131
