The Messenger of Allah ﷺ said, "Fasting while traveling is not an act of righteousness."
قال رسول الله ﷺ: ليس من البر الصيام في السفر.
Ibn Majah related it (1665), and Ibn Hibban graded it sahih (3548), as did Tahawi (3136), all of them from the hadith of Muhammad bin Musaffa Himsi, who said, "Muhammad bin Harb narrated to us, from Ubaydullah bin Umar, from Nafi, from Ibn Umar," and he mentioned it. Its chain of transmission is sahih. Busiri also graded it sahih in Zawaid.