صحیح ابن حبان
Ibn Hibban
كتاب الصلاة
Book of Prayer
فصل في الصلاة على الدابة - ذكر البيان بأن المسافر مباح له أن يتنفل على راحلته وإن كان ظهره إلى القبلة
Section on prayer on a riding animal – clarification that a traveler is permitted to perform voluntary prayers on his mount even if his back is to the qiblah
1 hadith
Hadith 2521
Sayyiduna Jabir bin Abdullah (may Allah be pleased with both of them) narrates: We participated in a battle along with the Prophet Muhammad (peace be upon him), and the Prophet (peace be upon him) would perform voluntary prayers on his mount, which would be facing towards the east. But when he had to perform an obligatory prayer, he would dismount and perform it facing the Qiblah.