What did the Prophet Muhammad (saw) say about the day of Al-Khandaq?
 Narrated `Ali:                     On the day of Al-Khandaq (i.e. Trench), the Prophet 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."