Bukhari Collection: ::Book Number 4:: Hadith # 182
Narrated `Ali:When it was the day of the battle of Al-Ahzab (i.e. the clans), Allah's Apostle said, "O Allah! Fill their (i.e. the infidels') houses and graves with fire as they busied us so much that we did not perform the prayer (i.e. `Asr) till the sun set."