the Messenger of Allah saw some people gathered around a man, so he asked (what was happening) and they said: "It is a man who is exhausted because of fasting." The Messenger of Allah said: "It is not righteousness to fast when traveling."
Sunan an-Nasa'i Book 22, Hadith 168
← Previous Hadith "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.

Sunan an-Nasa'i Book 22, Hadith 167 Next Hadith → the Messenger of Allah passed by a man in the shade of a tree on whom water was being sprinkled. He said: "What is the matter with your companion?" They said: "O Messenger of Allah, he is fasting." He said: "It is not righteousness to fast when traveling. Take to the concession which Allah has granted you, accept it."

Sunan an-Nasa'i Book 22, Hadith 169