أَخْبَرَنَا النَّضْرُ، نا شُعْبَةُ، نا مُحَمَّدُ بْنُ زِيَادٍ، قَالَ: سَمِعْتُ أَبَا هُرَيْرَةَ، يَقُولُ: قَالَ رَسُولُ اللَّهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ: صُومُوا لِرُؤْيَةِ الْهِلَالِ وَأَفْطِرُوا لِرُؤْيَةِ الْهِلَالِ، أَوْ قَالَ: صُومُوا حِينَ تَرَوْهُ وَأَفْطِرُوا إِذَا رَأَيْتُمُوهُ، فَإِنْ عُمِّيَ عَلَيْكُمْ فَعُدُّوا ثَلَاثِينَ.
Sayyiduna Abu Huraira (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: "Begin fasting upon sighting the moon, and stop fasting upon sighting the moon." Or he said: "When you see it, then begin fasting, and when you see (the Shawwal moon), then stop fasting. If the sky is cloudy for you, then complete the count to thirty."