"On the Day of Al-Khandaq (the battle of the Trench), Umar bin Al-Khattab came cursing the disbelievers of Quraish and said: 'O Allah's Messenger! I could not offer he Asr prayer until the sun was about to set.' The Prophet said: 'By Allah! I too have not offered the Salat.'" So he said: "We descended into Buthan, Allah's Messenger performed Wudu and we too performed Wudu. Allah's Messenger prayed Asr after the sun had set, then after it he prayed Maghrib."