Sunan an-Nasa'i, Volume 3, Book 22, Hadith 2315 (DarusSalam)

It was narrated that Ibn 'Abbas said: "The Messenger Allah went out in the year of the Conquest, fasting during Ramadan. Then when he was in Al-Kadid, he broke his fast."

أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنِ الزُّهْرِيِّ، عَنْ عُبَيْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ، عَنِ ابْنِ عَبَّاسٍ، قَالَ خَرَجَ رَسُولُ اللَّهِ صلى الله عليه وسلم عَامَ الْفَتْحِ صَائِمًا فِي رَمَضَانَ حَتَّى إِذَا كَانَ بِالْكَدِيدِ أَفْطَرَ ‏.‏

sunnah.com