The Book of Fasting
22/46. Chapter:
It is disliked to fast when traveling
Sunan an-Nasai
أَخْبَرَنِي إِبْرَاهِيمُ بْنُ يَعْقُوبَ، قَالَ حَدَّثَنَا مُحَمَّدُ بْنُ كَثِيرٍ، عَنِ الأَوْزَاعِيِّ، عَنِ الزُّهْرِيِّ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " لَيْسَ مِنَ الْبِرِّ الصِّيَامُ فِي السَّفَرِ " . قَالَ أَبُو عَبْدِ الرَّحْمَنِ هَذَا خَطَأٌ وَالصَّوَابُ الَّذِي قَبْلَهُ لاَ نَعْلَمُ أَحَدًا تَابَعَ ابْنَ كَثِيرٍ عَلَيْهِ .
It was narrated that Saeed bin Al-Musayyab said: "The Messenger of Allah said: 'It is not righteousness to fast when traveling."' (Sahih) Abu 'Abdur-Rahman (An-Nasai) said: This is a mistake, and what is correct is the one that is before it. We do not know of anyone who followed up Ibn Kathir.
Reference : Sunan an-Nasa'i 2256In-book reference : Book 22, Hadith 167English translation : Vol. 3, Book 22, Hadith 2258