Sahih Bukhari Volume 3, Book 30, Hadith 1989

حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَحْيَى، عَنْ مَالِكٍ، قَالَ حَدَّثَنِي سَالِمٌ، قَالَ حَدَّثَنِي عُمَيْرٌ، مَوْلَى أُمِّ الْفَضْلِ أَنَّ أُمَّ، الْفَضْلِ حَدَّثَتْهُ ح وَحَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ أَخْبَرَنَا مَالِكٌ عَنْ أَبِي النَّضْرِ مَوْلَى عُمَرَ بْنِ عُبَيْدِ اللَّهِ عَنْ عُمَيْرٍ مَوْلَى عَبْدِ اللَّهِ بْنِ الْعَبَّاسِ عَنْ أُمِّ الْفَضْلِ بِنْتِ الْحَارِثِ أَنَّ نَاسًا تَمَارَوْا عِنْدَهَا يَوْمَ عَرَفَةَ فِي صَوْمِ النَّبِيِّ صلى الله عليه وسلم فَقَالَ بَعْضُهُمْ هُوَ صَائِمٌ‏.‏ وَقَالَ بَعْضُهُمْ لَيْسَ بِصَائِمٍ‏.‏ فَأَرْسَلَتْ إِلَيْهِ بِقَدَحِ لَبَنٍ وَهْوَ وَاقِفٌ عَلَى بَعِيرِهِ فَشَرِبَهُ‏

Narrated By Um Al-Fadl bint Al-Harith : "While the people were with me on the day of 'Arafat they differed as to whether the Prophet was fasting or not; some said that he was fasting while others said that he was not fasting. So, I sent to him a bowl full of milk while he was riding over his camel and he drank it."