Narrated Ubaidullah bin `Abdullah bin `Utba:Ibn `Abbas said, Allah's Messenger (ﷺ) fought the Ghazwa (i.e. battles of Al-Fath during Ramadan." Narrated Az-Zuhri: Ibn Al-Musaiyab (also) said the same. Ibn `Abbas added, "The Prophet (ﷺ) fasted and when he reached Al-Kadid, a place where there is water between Kudaid and 'Usfan, he broke his fast and did not fast afterwards till the whole month had passed away.
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، حَدَّثَنَا اللَّيْثُ، قَالَ حَدَّثَنِي عُقَيْلٌ، عَنِ ابْنِ شِهَابٍ، قَالَ أَخْبَرَنِي عُبَيْدُ اللَّهِ بْنُ عَبْدِ اللَّهِ بْنِ عُتْبَةَ، أَنَّ ابْنَ عَبَّاسٍ، أَخْبَرَهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم غَزَا غَزْوَةَ الْفَتْحِ فِي رَمَضَانَ. قَالَ وَسَمِعْتُ ابْنَ الْمُسَيَّبِ يَقُولُ مِثْلَ ذَلِكَ. وَعَنْ عُبَيْدِ اللَّهِ أَنَّ ابْنَ عَبَّاسِ ـ رضى الله عنهما ـ قَالَ صَامَ رَسُولُ اللَّهِ صلى الله عليه وسلم حَتَّى إِذَا بَلَغَ الْكَدِيدَ ـ الْمَاءَ الَّذِي بَيْنَ قُدَيْدٍ وَعُسْفَانَ ـ أَفْطَرَ، فَلَمْ يَزَلْ مُفْطِرًا حَتَّى انْسَلَخَ الشَّهْرُ.
Bukhari
Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi) • Hadith 309