Sahih al-Bukhari 4864
صحيح البخاري#4864Sahihحَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَحْيَى، عَنْ شُعْبَةَ، وَسُفْيَانَ، عَنِ الأَعْمَشِ، عَنْ إِبْرَاهِيمَ، عَنْ أَبِي مَعْمَرٍ، عَنِ ابْنِ مَسْعُودٍ، قَالَ انْشَقَّ الْقَمَرُ عَلَى عَهْدِ رَسُولِ اللَّهِ صلى الله عليه وسلم فِرْقَتَيْنِ، فِرْقَةً فَوْقَ الْجَبَلِ وَفِرْقَةً دُونَهُ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " اشْهَدُوا ".
Narrated Ibn Masud:During the lifetime of Allah's Messenger (ﷺ) the moon was split into two parts; one part remained over the mountain, and the other part went beyond the mountain. On that, Allah's Messenger (ﷺ) said, "Witness this miracle
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:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 65:385