Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) narrates: The Prophet Muhammad (peace and blessings be upon him) saw a man around whom people had gathered and were providing shade for him. The Prophet (peace and blessings be upon him) inquired: What is the matter? The people replied: This man is observing a fast. The Prophet (peace and blessings be upon him) said: It is not an act of righteousness that you fast while traveling.
Hadith Referenceصحیح ابن حبان / كتاب الصوم / 3552
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - «صحيح أبي داود» (2082): ق.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح على شرط الشيخين