Do not criticize one who fasts, nor one who breaks his fast, for the Messenger of Allah ﷺ both fasted and broke his fast while traveling.
لا تعب على من صام، ولا على من أفطر، فقد صام رسول الله ﷺ في السفر وأفطر.
Muslim narrated it in the Book of Fasting (1113: 89), from Abu Kurayb, who said, Waki narrated to us, from Sufyan, from Abdul-Kareem, from Tawus, from Ibn Abbas, and he mentioned it.