"I heard the Messenger of Allah say; 'It is not righteousness to fast when traveling."' (Using translation from Nasāʾī 2255)  

سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ «لَيْسَ مِنَ الْبِرِّ الصِّيَامُ فِي السَّفَرِ»  

"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. (Using translation from Nasāʾī 2256)   

قَالَ رَسُولُ اللهِ ﷺ «لَيْسَ مِنَ الْبِرِّ الصِّيَامُ فِي السَّفَرِ» قَالَ أَبُو عَبْدِ الرَّحْمَنِ هَذَا الْحَدِيثُ خَطَأٌ وَلَا نَعْلَمُ أَحَدًا تَابَعَ مُحَمَّدَ بْنَ كَثِيرٍ عَلَى هَذَا الْإِسْنَادِ وَاللهُ أَعْلَمُ وَالصَّوَابُ الَّذِي قَبْلَهُ