صحیح ابن حبان
Ibn Hibban
كتاب الصوم
Book of Fasting
باب صوم المسافر - ذكر الخبر الدال على أن الصوم في السفر إنما كره مخافة أن يضعف المرء دون أن يكون استعماله ضدا للبر
Chapter on Fasting While Traveling - Fasting while traveling is disliked only if it weakens a person, not as an act against righteousness
1 hadith
Hadith 3553
Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) narrates: On the occasion of the Battle of Tabuk, we set out with the Prophet Muhammad (peace be upon him). This battle is also called the Battle of Hardship. While we were traveling after the sun had risen, we came upon a place where some people were gathered under the shade of a tree. These people said: O Messenger of Allah (peace be upon him), this person is fasting, and his fast is causing him hardship. The Prophet Muhammad (peace be upon him) said: It is not an act of righteousness that you fast while traveling.