Jaabir Radiyallahu 'Anhu says:
"Rasulullah Sallallahu 'Alayhi Wasallam came to visit me (while I was ill). He did not come on the back of a mule, or on a Turkish horse". (i.e. He did not come on defective or an expensive conveyance, but came on foot). (ID)
English reference (ID): Book 46, Hadith 321 (ID)
Arabic reference (ID): Book 47, Hadith 338 (ID)