Majma al-Zawaid — Hadith 13225

Sayyiduna Mu'adh bin Anas (may Allah be pleased with him) narrates about the Prophet (peace and blessings be upon him) that he passed by some people who were sitting on their animals and mounts, standing still, and he said to them: "Ride them while they are sound and leave them while they are sound. Do not make them chairs for your conversations in the roads and markets, for sometimes the mount is better than its rider and remembers Allah Almighty more than he does."
Ahmad and al-Tabarani recorded it. The narrators of one of Ahmad's chains are the narrators of the Sahih, except Sahl bin Mu'adh bin Anas, whom Ibn Hibban declared thiqah (trustworthy), though there is weakness in him.