Abu al-Musabbih al-Himsi said: We were travelling in a group whose commander was Malik bin Abdullah. He passed by Sayyiduna Jabir bin Abdullah (may Allah be pleased with him), who was walking on foot leading his mule, and Malik bin Abdullah said: Why do you not ride, when Allah has given you a mount? Jabir (may Allah be pleased with him) said: I heard the Messenger of Allah (peace and blessings be upon him) say: "The feet that become dusty in the path of Allah, Allah makes the Fire of Hell forbidden for them." My mount is in good condition, and I am independent of my people. At that, the people dismounted from their mounts. I have never seen more people on foot than on that day.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18516