Sunan an Nasai 2138
The Book of Fasting
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
Grading: Abu Ghuddah: Sahih Isnaad · Al-Albani: Sahih Isnaad · Zubair Ali Zai: Sahih
Text from the public-domain hadith-api dataset. Numbering follows that dataset and can differ by a few from some printed editions — check the wording, not only the number.