أَخْبَرَنَا إِسْمَاعِيلُ بْنُ مَسْعُودٍ، وَمُحَمَّدُ بْنُ عَبْدِ الأَعْلَى، قَالاَ حَدَّثَنَا خَالِدٌ، - وَهُوَ ابْنُ الْحَارِثِ - عَنْ هِشَامٍ، عَنْ يَحْيَى بْنِ أَبِي كَثِيرٍ، عَنْ أَبِي سَلَمَةَ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ جَابِرِ بْنِ عَبْدِ اللَّهِ، أَنَّ عُمَرَ بْنَ الْخَطَّابِ، يَوْمَ الْخَنْدَقِ بَعْدَ مَا غَرَبَتِ الشَّمْسُ جَعَلَ يَسُبُّ كُفَّارَ قُرَيْشٍ وَقَالَ يَا رَسُولَ اللَّهِ مَا كِدْتُ أَنْ أُصَلِّيَ حَتَّى كَادَتِ الشَّمْسُ تَغْرُبُ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ فَوَاللَّهِ مَا صَلَّيْتُهَا ‏"‏ ‏.‏ فَنَزَلْنَا مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم إِلَى بُطْحَانَ فَتَوَضَّأَ لِلصَّلاَةِ وَتَوَضَّأْنَا لَهَا فَصَلَّى الْعَصْرَ بَعْدَ مَا غَرَبَتِ الشَّمْسُ ثُمَّ صَلَّى بَعْدَهَا الْمَغْرِبَ ‏.‏

It was narrated from Jabir bin Abdullah that: On the Day of Al-Khandaq, after the sun had set, Umar bin Al-Khattab started cursing the disbelievers of the Quraish and said: "O Messenger of Allah, I was hardly able to pray until the sun set." The Messenger of Allah (PBUH) said: "By Allah, I did not pray." So we went down with the Messenger of Allah (PBUH) to Buthan. He performed wudu' for prayer and so did we, and he prayed 'Asr after the sun had set, then he prayed Maghrib after that." Translation Not Available

Book Ref: Sunan An Nisai Book 13 Hadith 1366
Web Ref:  Sunan An Nisai Vol 2 Book 13 Hadith 1367