حَدَّثَنَا أَبُو مَعْمَرٍ عَبْدُ اللَّهِ بْنُ عَمْرٍو، حَدَّثَنَا عَبْدُ الْوَارِثِ، حَدَّثَنَا مُحَمَّدُ بْنُ إِسْحَاقَ، عَنْ مُحَمَّدِ بْنِ جَعْفَرٍ، عَنِ ابْنِ عَبْدِ اللَّهِ بْنِ أُنَيْسٍ، عَنْ أَبِيهِ، قَالَ بَعَثَنِي رَسُولُ اللَّهِ صلى الله عليه وسلم إِلَى خَالِدِ بْنِ سُفْيَانَ الْهُذَلِيِّ - وَكَانَ نَحْوَ عُرَنَةَ وَعَرَفَاتٍ - فَقَالَ ‏"‏ اذْهَبْ فَاقْتُلْهُ ‏"‏ ‏.‏ قَالَ فَرَأَيْتُهُ وَحَضَرَتْ صَلاَةُ الْعَصْرِ فَقُلْتُ إِنِّي لأَخَافُ أَنْ يَكُونَ بَيْنِي وَبَيْنَهُ مَا إِنْ أُؤَخِّرُ الصَّلاَةَ فَانْطَلَقْتُ أَمْشِي وَأَنَا أُصَلِّي أُومِئُ إِيمَاءً نَحْوَهُ فَلَمَّا دَنَوْتُ مِنْهُ قَالَ لِي مَنْ أَنْتَ قُلْتُ رَجُلٌ مِنَ الْعَرَبِ بَلَغَنِي أَنَّكَ تَجْمَعُ لِهَذَا الرَّجُلِ فَجِئْتُكَ فِي ذَاكَ ‏.‏ قَالَ إِنِّي لَفِي ذَاكَ فَمَشَيْتُ مَعَهُ سَاعَةً حَتَّى إِذَا أَمْكَنَنِي عَلَوْتُهُ بِسَيْفِي حَتَّى بَرَدَ ‏.‏

Narrated 'Abd Allah b. Unais: The Messenger of Allah (PBUH) sent me to Khalid b. Sufyan al-Hudhail. This was towards 'Uranah and 'Arafat. He (the Prophet) said: Go and kill him. I saw him when the time of the afternoon prayer had come. I said: I am afraid if a fight takes place between me and him (Khalid b. Sufyan), that might delay the prayer. I proceeded walking towards him while I was praying by making a sign. When I reached near him, he said to me: Who are you ? I replied: A man from the Arabs; it came to me that you were gathering (any army) for this man (i.e. Prophet). Hence I came to you in connection with this matter. He said: I am (engaged) in this (work). I then walked along with him for a while ; when it became convenient for me, I dominated him with my sword until he became cold (dead). Translation Not Available

Book Ref: Sunan Abi Dawud Book 4 Hadith 1249
Web Ref:  Sunan Abi Dawud Book 4 Hadith 1244