أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ أَنْبَأَنَا سُفْيَانُ، عَنِ الزُّهْرِيِّ، عَنْ صَفْوَانَ بْنِ عَبْدِ اللَّهِ، عَنْ أُمِّ الدَّرْدَاءِ، عَنْ كَعْبِ بْنِ عَاصِمٍ، قَالَ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏"‏ لَيْسَ مِنَ الْبِرِّ الصِّيَامُ فِي السَّفَرِ ‏"‏ ‏.‏
Translation
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.