Al-Kāfi - Volume 4 > Those Who Do or Do Not Have to Break Their Fast on a Journey
Hadith #3

3ـ عِدَّةٌ مِنْ أَصْحَابِنَا عَنْ سَهْلِ بْنِ زِيَادٍ عَنِ الْحَسَنِ بْنِ مَحْبُوبٍ عَنْ أَبِي أَيُّوبَ عَنْ مُحَمَّدِ بْنِ مَرْوَانَ عَنْ أَبِي عَبْدِ الله (عَلَيْهِ السَّلاَم) قَالَ سَمِعْتُهُ يَقُولُ مَنْ سَافَرَ قَصَّرَ وَأَفْطَرَ إِلاَّ أَنْ يَكُونَ رَجُلاً سَفَرُهُ إِلَى صَيْدٍ أَوْ فِي مَعْصِيَةِ الله أَوْ رَسُولاً لِمَنْ يَعْصِي الله أَوْ فِي طَلَبِ شَحْنَاءَ أَوْ سِعَايَةِ ضَرَرٍ عَلَى قَوْمٍ مُسْلِمِينَ.

3. A number of our people have narrated from Sahl ibn Ziyad from al-Hassan ibn Mahbub from abu Ayyub from Muhammad ibn Marwan who has said the following: “I once heard abu ‘Abd Allah, ‘Alayhi al-Salam, say, ‘On a journey one must reduce Salat (prayer) and stop fasting unless one’s journey is because of hunting or it is in disobedience to Allah or is a messenger of one who disobeys Allah or is for seeking enmity and has slanderous reasons to cause harms to Muslims.’”