It is narrated from Sayyiduna Mu'adh bin Anas al-Juhani (may Allah be pleased with him): The Messenger of Allah (peace and blessings be upon him) passed by some people who had halted, (sitting) on their mounts and camels. The Prophet (peace and blessings be upon him) said: "Ride them while they are sound, and dismount from them while they are sound, and do not make them chairs for your conversations and your gatherings, for many a mount is better than its rider and remembers Allah more than he does."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17567