كتاب المغازى
64  
Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
(29)
Chapter: The Ghazwa of Al-Khandaq or Al-Ahzab Battle
(29)
باب غَزْوَةُ الْخَنْدَقِ وَهْىَ الأَحْزَابُ
Sahih al-Bukhari 4111

Narrated `Ali:

On the day of Al-Khandaq (i.e. Trench), the Prophet (ﷺ) said '(Let) Allah fill their (i.e. the infidels') houses and graves with fire just as they have prevented us from offering the Middle Prayer (i.e. `Asr prayer) till the sun had set."

حَدَّثَنَا إِسْحَاقُ، حَدَّثَنَا رَوْحٌ، حَدَّثَنَا هِشَامٌ، عَنْ مُحَمَّدٍ، عَنْ عَبِيدَةَ، عَنْ عَلِيٍّ ـ رضى الله عنه ـ عَنِ النَّبِيِّ صلى الله عليه وسلم أَنَّهُ قَالَ يَوْمَ الْخَنْدَقِ ‏ "‏ مَلأَ اللَّهُ عَلَيْهِمْ بُيُوتَهُمْ وَقُبُورَهُمْ نَارًا كَمَا شَغَلُونَا عَنْ صَلاَةِ الْوُسْطَى حَتَّى غَابَتِ الشَّمْسُ ‏"‏‏.‏
Reference : Sahih al-Bukhari 4111
In-book reference : Book 64, Hadith 155
USC-MSA web (English) reference : Vol. 5, Book 59, Hadith 437
  (deprecated numbering scheme)