Sahih al-Bukhari, Volume 5, Book 59, Hadith 575 (USC-MSA) ⓘ

Narrated Ibn `Abbas: Allah's Messenger set out towards Hunain in the month of Ramadan and some of the people were fasting while some others were not fasting, and when the Prophet mounted his she-camel, he asked for a tumbler of milk or water and put it on the palm of his hand or on his she-camel and then the people looked at him; and those who were not fasting told those who were fasting, to break their fast (i.e. as the Prophet had done so).

حَدَّثَنِي عَيَّاشُ بْنُ الْوَلِيدِ، حَدَّثَنَا عَبْدُ الأَعْلَى، حَدَّثَنَا خَالِدٌ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ، قَالَ خَرَجَ النَّبِيُّ صلى الله عليه وسلم فِي رَمَضَانَ إِلَى حُنَيْنٍ، وَالنَّاسُ مُخْتَلِفُونَ فَصَائِمٌ وَمُفْطِرٌ، فَلَمَّا اسْتَوَى عَلَى رَاحِلَتِهِ دَعَا بِإِنَاءٍ مِنْ لَبَنٍ أَوْ مَاءٍ، فَوَضَعَهُ عَلَى رَاحَتِهِ أَوْ عَلَى رَاحِلَتِهِ، ثُمَّ نَظَرَ إِلَى النَّاسِ فَقَالَ الْمُفْطِرُونَ لِلصُّوَّامِ أَفْطِرُوا‏.‏

Ibn `Abbas added: "The Prophet went (to Hunain) in the year of the Conquest (of Mecca).

وَقَالَ عَبْدُ الرَّزَّاقِ أَخْبَرَنَا مَعْمَرٌ، عَنْ أَيُّوبَ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ خَرَجَ النَّبِيُّ صلى الله عليه وسلم عَامَ الْفَتْحِ‏.‏ وَقَالَ حَمَّادُ بْنُ زَيْدٍ عَنْ أَيُّوبَ عَنْ عِكْرِمَةَ عَنِ ابْنِ عَبَّاسٍ عَنِ النَّبِيِّ صلى الله عليه وسلم‏.‏