Sahih Muslim Book: 14, Hadith: 2554

وَحَدَّثَنِي زُهَيْرُ بْنُ حَرْبٍ، حَدَّثَنَا إِسْمَاعِيلُ، عَنْ أَيُّوبَ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، – رضى الله عنهما – قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ “‏ إِنَّمَا الشَّهْرُ تِسْعٌ وَعِشْرُونَ فَلاَ تَصُومُوا حَتَّى تَرَوْهُ وَلاَ تُفْطِرُوا حَتَّى تَرَوْهُ فَإِنْ غُمَّ عَلَيْكُمْ فَاقْدِرُوا لَهُ ‏”‏ ‏.‏ Ibn’Umar (Allah be pleased with-both of them) reported Allah’s Messenger (may peace be upon him) as saying:The month of Ramadan may consist of twenty-nine days. So do not fast till you have sighted it (the new moon) and do not break fast, till you have sighted it (the new moon of Shawwal), and if the sky is cloudy for you, then calculate. Chain : Zuhayr bin Harb – Isma’il bin Ibrahim – Ibn ‘Aliya – Ayoub al-Sakhtiyani – Nafie’ – ibn Umar Data Source Disclaimer: The data presented on this website has been meticulously collected from Sunnah.com , a recognized and authentic source....