Sahih al-Bukhari 4279
Sahih al-Bukhari · Book 64: Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi) · The Ghazwa of Al-Fath during Ramadan
Narrated Tawus:
حَدَّثَنَا عَلِيُّ بْنُ عَبْدِ اللَّهِ ، حَدَّثَنَا جَرِيرٌ ، عَنْ مَنْصُورٍ ، عَنْ مُجَاهِدٍ ، عَنْ طَاوُسٍ ، عَنِ ابْنِ عَبَّاسٍ ، قَالَ سَافَرَ رَسُولُ اللَّهِ صلى الله عليه وسلم فِي رَمَضَانَ، فَصَامَ حَتَّى بَلَغَ عُسْفَانَ، ثُمَّ دَعَا بِإِنَاءٍ مِنْ مَاءٍ فَشَرِبَ نَهَارًا، لِيُرِيَهُ النَّاسَ، فَأَفْطَرَ حَتَّى قَدِمَ مَكَّةَ. قَالَ وَكَانَ ابْنُ عَبَّاسٍ يَقُولُ صَامَ رَسُولُ اللَّهِ صلى الله عليه وسلم فِي السَّفَرِ وَأَفْطَرَ، فَمَنْ شَاءَ صَامَ، وَمَنْ شَاءَ أَفْطَرَ.
Ibn `Abbas said, "Allah's Messenger (ﷺ) travelled in the month of Ramadan and he fasted till he reached (a place called) 'Usfan, then he asked for a tumbler of water and drank it by the daytime so that the people might see him. He broke his fast till he reached Mecca." Ibn `Abbas used to say, "Allah's Apostle fasted and sometimes did not fast while traveling, so one may fast or may not (on journeys)"