Narrated Jabir bin `Abdullah: On the day of Al-Khandaq (the trench), `Umar bin Al-Khattab went to the Prophet and said, O Allah's Apostle! By Allah, I could not pray (the `Asr) till the sun had set. `Umar told this to the Prophet at the time when a fasting person had done Iftar (taken his meals). The Prophet then went to Buthan and I was with him. He performed ablution and offered the `Asr prayer after the sun had set and then the Maghrib prayer.