The Book of Fasting
22/17. Chapter:
Mentioning The Differences Reported From Yahya Bin Abi Kathir In The Narration Of Abu Salamah about that
Sunan an-Nasai
أَخْبَرَنَا أَبُو دَاوُدَ، قَالَ حَدَّثَنَا هَارُونُ، قَالَ حَدَّثَنَا عَلِيٌّ، - هُوَ ابْنُ الْمُبَارَكِ - قَالَ حَدَّثَنَا يَحْيَى، عَنْ أَبِي سَلَمَةَ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " الشَّهْرُ يَكُونُ تِسْعَةً وَعِشْرِينَ وَيَكُونُ ثَلاَثِينَ فَإِذَا رَأَيْتُمُوهُ فَصُومُوا وَإِذَا رَأَيْتُمُوهُ فَأَفْطِرُوا فَإِنْ غُمَّ عَلَيْكُمْ فَأَكْمِلُوا الْعِدَّةَ " .
It was narrated that Abu Hurairah said: "The Messenger of Allah said: The month may be twenty-nine days or it may be thirty. When you see it, then stop fasting, and it is obscured from you (too cloudy), then complete the count."'
Reference : Sunan an-Nasa'i 2138In-book reference : Book 22, Hadith 49English translation : Vol. 3, Book 22, Hadith 2140