Full Sharh — Sunan an-Nasa'i 2128
أَخْبَرَنَا مُحَمَّدُ بْنُ حَاتِمٍ، قَالَ حَدَّثَنَا حِبَّانُ، قَالَ حَدَّثَنَا عَبْدُ اللَّهِ، عَنِ الْحَجَّاجِ بْنِ أَرْطَاةَ، عَنْ مَنْصُورٍ، عَنْ رِبْعِيٍّ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِذَا رَأَيْتُمُ الْهِلاَلَ فَصُومُوا وَإِذَا رَأَيْتُمُوهُ فَأَفْطِرُوا فَإِنْ غُمَّ عَلَيْكُمْ فَأَتِمُّوا شَعْبَانَ ثَلاَثِينَ إِلاَّ أَنْ تَرَوُا الْهِلاَلَ قَبْلَ ذَلِكَ ثُمَّ صُومُوا رَمَضَانَ ثَلاَثِينَ إِلاَّ أَنْ تَرَوُا الْهِلاَلَ قَبْلَ ذَلِكَ " .
English Translation
It was narrated that Ribi said; "the Messenger of Allah said:"The Messenger of Allah said: 'When you see the crescent then fast, and when you see it, then stop fasting. If it is too cloudy then complete Shaban as thirty days, unless you see the crescent before that, then fast Ramadan as thirty days, unless you see the new crescent before that
Source
Sunan an-Nasa'i(سنن النسائي)
The Book of Fasting
Hadith Number
2128
Grade
Sahih Lighairihi