The Messenger of Allah ﷺ said, "Do not use riding animals as chairs, for many a mount carrying a rider remembers Allah the Exalted more than the one riding it."
حدثنا حسن حدثنا ابن لهيعة حدثنا يزيد بن أبي حبيب
أن رسول الله ﷺ قال لا تتخذوا الدواب كراسي فرب مركوبة عليها هي أكثر ذكرا لله تعالى من راكبها
Its isnad is hasan because of Ibn Lahia, and the hadith has already appeared at 15562.