صَحِيحُ مُسْلِمٍ
Sahih Muslim 1115 a
The Book of Fasting
It is permissible to fast or not to fast during Ramadan for one who is travelling for no sinful purpose, if his journey is two stages or further. But it is better for the one who is able to fast without suffering any harm to do so, and the one for whom it is difficult may break the fast
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَمُحَمَّدُ بْنُ الْمُثَنَّى، وَابْنُ، بَشَّارٍ جَمِيعًا عَنْ مُحَمَّدِ، بْنِ جَعْفَرٍ - قَالَ أَبُو بَكْرٍ حَدَّثَنَا غُنْدَرٌ، - عَنْ شُعْبَةَ، عَنْ مُحَمَّدِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ سَعْدٍ، عَنْ مُحَمَّدِ بْنِ عَمْرِو بْنِ الْحَسَنِ، عَنْ جَابِرِ بْنِ عَبْدِ اللَّهِ، - رضى الله عنهما - قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم فِي سَفَرٍ فَرَأَى رَجُلاً قَدِ اجْتَمَعَ النَّاسُ عَلَيْهِ وَقَدْ ظُلِّلَ عَلَيْهِ فَقَالَ " مَا لَهُ " . قَالُوا رَجُلٌ صَائِمٌ . فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " لَيْسَ مِنَ الْبِرِّ أَنْ تَصُومُوا فِي السَّفَرِ " .
Jabir b. 'Abdullah (Allah be pleased with both of them) reported that in the course of a journey Allah's Messenger (ﷺ) saw a man, people crowding around him and providing him a shade. Upon this he (the Prophet) said: What is the matter with him? They said: He is a person observing fast. Whereupon the Messenger of Allah (ﷺ) said: It is no righteousness that you fast on journey.
Sahih Muslim, 1115 aSahihصحيح