وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ سُمَىٍّ، مَوْلَى أَبِي بَكْرِ بْنِ عَبْدِ الرَّحْمَنِ عَنْ أَبِي بَكْرِ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ بَعْضِ، أَصْحَابِ رَسُولِ اللَّهِ صلى الله عليه وسلم أَنَّ 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 الْمَاءَ عَلَى رَأْسِهِ مِنَ الْعَطَشِ أَوْ مِنَ الْحَرِّ ثُمَّ قِيلَ لِرَسُولِ اللَّهِ صلى الله عليه وسلم يَا رَسُولَ اللَّهِ إِنَّ طَائِفَةً مِنَ النَّاسِ قَدْ صَامُوا حِينَ صُمْتَ - قَالَ - فَلَمَّا كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم بِالْكَدِيدِ دَعَا بِقَدَحٍ فَشَرِبَ فَأَفْطَرَ النَّاسُ ‏.‏

Yahya related to me from Malik from Sumayy, the mawla of Abu Bakribn Abd ar-Rahman, from Abu Bakr ibn Abd ar-Rahman from one of thecompanions of the Messenger of Allah, that the Messenger of Allah, mayAllah bless him and grant him peace, ordered everyone to break thefast on the journey he made in the year of the conquest saying, "Bestrong for your enemy," while the Messenger of Allah, may Allah blesshim and grant him peace, kept on fasting. Abu Bakr said that the onewho related this to him said, "I saw the Messenger of Allah, may Allahbless him and grant him peace, pouring water over his head at al-Arj,either from thirst or from the heat. Then some one said to theMessenger of Allah, may Allah bless him and grant him peace,'Messenger of Allah, a group of people kept on fasting when you did.'Then when the Messenger of Allah was at al-Kadid, he asked for adrinking-bowl and drank, and everyone broke the fast." Translation Not Available

Book Ref: Muwatta Imam Malik Book 18 Hadith 656
Web Ref:  Muwatta Imam Malik Book 18 Hadith 22