Language:
كتاب الصوم
30  
Fasting
(34)
Chapter: If a person observed Saum for some days and then went on a journey.
(34)
باب إِذَا صَامَ أَيَّامًا مِنْ رَمَضَانَ ثُمَّ سَافَرَ
Sahih al-Bukhari 1944

Narrated Ibn `Abbas:

Allah's Messenger (ﷺ) set out for Mecca in Ramadan and he fasted, and when he reached Al-Kadid, he broke his fast and the people (with him) broke their fast too. (Abu `Abdullah said, "Al-Kadid is a land covered with water between Usfan and Qudaid.")

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، أَخْبَرَنَا مَالِكٌ، عَنِ ابْنِ شِهَابٍ، عَنْ عُبَيْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ بْنِ عُتْبَةَ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم خَرَجَ إِلَى مَكَّةَ فِي رَمَضَانَ فَصَامَ حَتَّى بَلَغَ الْكَدِيدَ أَفْطَرَ، فَأَفْطَرَ النَّاسُ‏.‏ قَالَ أَبُو عَبْدِ اللَّهِ وَالْكَدِيدُ مَاءٌ بَيْنَ عُسْفَانَ وَقُدَيْدٍ‏.‏
Reference : Sahih al-Bukhari 1944
In-book reference : Book 30, Hadith 51
USC-MSA web (English) reference : Vol. 3, Book 31, Hadith 165
  (deprecated numbering scheme)