Thawban (may Allah be pleased with him), the freed slave of the Messenger of Allah (peace and blessings be upon him), said that he went out with a funeral and saw people going out riding on their mounts. Thawban (may Allah be pleased with him) said to them: "Are you not ashamed? The angels of Allah are on their feet while you are riding!"
This, with this chain, is what is preserved (mahfuz): mawquf (stopping at the Companion).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6855