Sunan an-Nasai 17054
In-book no 2318أَخْبَرَنَا 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 .
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."