What led the Prophet Muhammad (peace be upon him) and his companions to offer the `Asr prayer after the sun had set?
 Narrated Jabir bin `Abdullah:                     `Umar bin Al-Khattab came on the day of Al-Khandaq after the sun had set and he was abusing the infidels of Quraish saying, "O Allah's Apostle! I was unable to offer the (`Asr) prayer till the sun was about to set." The Prophet said, "By Allah, I have not offered this (i.e. `Asr) prayer." So we came down along with the Prophet to Buthan where he performed ablution for the prayer and then we performed the ablution for it. Then he offered the `Asr prayer after the sun had set, and after it he offered the Maghrib prayer.