Sunan Ibn Majah 1655
سنن ابن ماجه#1655Sahihحَدَّثَنَا أَبُو مَرْوَانَ الْعُثْمَانِيُّ، حَدَّثَنَا إِبْرَاهِيمُ بْنُ سَعْدٍ، عَنِ الزُّهْرِيِّ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ أَبِي هُرَيْرَةَ، قَالَ: قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " إِذَا رَأَيْتُمُ الْهِلاَلَ فَصُومُوا وَإِذَا رَأَيْتُمُوهُ فَأَفْطِرُوا فَإِنْ غُمَّ عَلَيْكُمْ فَصُومُوا ثَلاَثِينَ يَوْمًا " .
It was narrated from Abu Hurairah that the Messenger of Allah (ﷺ) said:“When you see the new crescent then fast, and when you see it then stop fasting. If it is cloudy then fast thirty days.”
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 7:18