حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ الْقَعْنَبِيُّ، عَنْ مَالِكٍ، عَنْ سُمَىٍّ، مَوْلَى أَبِي بَكْرِ بْنِ عَبْدِ الرَّحْمَنِ عَنْ أَبِي بَكْرِ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ بَعْضِ، أَصْحَابِ النَّبِيِّ صلى الله عليه وسلم قَالَ رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم أَمَرَ النَّاسَ فِي سَفَرِهِ عَامَ الْفَتْحِ بِالْفِطْرِ وَقَالَ ‏"‏ تَقَوَّوْا لِعَدُوِّكُمْ ‏"‏ ‏.‏ وَصَامَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏.‏ قَالَ أَبُو بَكْرٍ قَالَ الَّذِي حَدَّثَنِي لَقَدْ رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم بِالْعَرْجِ يَصُبُّ عَلَى رَأْسِهِ الْمَاءَ وَهُوَ صَائِمٌ مِنَ الْعَطَشِ أَوْ مِنَ الْحَرِّ ‏.‏

Narrated A Companion of the Prophet: AbuBakr ibn AbdurRahman reported on the authority of a Companion of the Prophet (PBUH): I saw the Prophet (PBUH) commanding the people while he was travelling on the occasion of the conquest of Mecca not to observe fast. He said: Be strong for your enemy. The Messenger of Allah (PBUH) fasted himself. Narrated AbuBakr: A man who narrated his tradition to me said: I have seen the Messenger of Allah (PBUH) in al-Arj pouring water over his head while he was fasting, either because of thirst or because of heat. Translation Not Available

Book Ref: Sunan Abi Dawud Book 14 Hadith 2365
Web Ref:  Sunan Abi Dawud Book 13 Hadith 2358