Yahya related to me from Malik from Humayd at-Tawil from Anas ibn Malik that when the Messenger of Allah, may Allah bless him and grant him peace, went out to Khaybar, he arrived there at night, and when he came upon a people by night, he did not attack until morning. In the morning, the jews came out with their spades and baskets. When they saw him, they said, "Muhammad! By Allah, Muhammad and his army!" The Messenger of Allah, may Allah bless him and grant him peace, said "Allah is greater! Khaybar is destroyed. When we come to a people, it is an evil morning for those who have been warned . "


وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ حُمَيْدٍ الطَّوِيلِ، عَنْ أَنَسِ بْنِ مَالِكٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم حِينَ خَرَجَ إِلَى خَيْبَرَ أَتَاهَا لَيْلاً وَكَانَ إِذَا أَتَى قَوْمًا بِلَيْلٍ لَمْ يُغِرْ حَتَّى يُصْبِحَ فَخَرَجَتْ يَهُودُ بِمَسَاحِيهِمْ وَمَكَاتِلِهِمْ فَلَمَّا رَأَوْهُ قَالُوا مُحَمَّدٌ وَاللَّهِ مُحَمَّدٌ وَالْخَمِيسُ ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ اللَّهُ أَكْبَرُ خَرِبَتْ خَيْبَرُ إِنَّا إِذَا نَزَلْنَا بِسَاحَةِ قَوْمٍ فَسَاءَ صَبَاحُ الْمُنْذَرِينَ ‏"‏ ‏.‏
USC-MSA web (English) reference : Book 21, Hadith 48
Arabic reference : Book 21, Hadith 1008