It is narrated from the first Shia Imam, Ali ibn Abitaleb (AS) who said: The Prophet of Islam (PBUH) used to sit on the floor on two knees and eat, as well as repair his shoes and sew patches on his clothes. The Prophet (PBUH) used to ride mules without saddle as well as giving lift to others [1].
[1] Nahjul Balaghah, Fayzul Islam, Sermon 195.