Sahih al-Bukhari 2945
صحيح البخاري#2945Sahihحَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، عَنْ مَالِكٍ، عَنْ حُمَيْدٍ، عَنْ أَنَسٍ ـ رضى الله عنه أَنَّ النَّبِيَّ صلى الله عليه وسلم خَرَجَ إِلَى خَيْبَرَ فَجَاءَهَا لَيْلاً، وَكَانَ إِذَا جَاءَ قَوْمًا بِلَيْلٍ لاَ يُغِيرُ عَلَيْهِمْ حَتَّى يُصْبِحَ، فَلَمَّا أَصْبَحَ، خَرَجَتْ يَهُودُ بِمَسَاحِيهِمْ وَمَكَاتِلِهِمْ، فَلَمَّا رَأَوْهُ قَالُوا مُحَمَّدٌ وَاللَّهِ، مُحَمَّدٌ وَالْخَمِيسُ. فَقَالَ النَّبِيُّ صلى الله عليه وسلم " اللَّهُ أَكْبَرُ، خَرِبَتْ خَيْبَرُ، إِنَّا إِذَا نَزَلْنَا بِسَاحَةِ قَوْمٍ فَسَاءَ صَبَاحُ الْمُنْذَرِينَ ".
Narrated Anas:The Prophet (ﷺ) set out for Khaibar and reached it at night. He used not to attack if he reached the people at night, till the day broke. So, when the day dawned, the Jews came out with their bags and spades. When they saw the Prophet; they said, "Muhammad and his army!" The Prophet (ﷺ) said, Allahu--Akbar! (Allah is Greater) and Khaibar is ruined, for whenever we approach a nation (i.e. enemy to fight) then it will be a miserable morning for those who have been warned
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: 56:157