The image comes from the 《
左传》: Duke Jing of Qi once played the ox for his little son, holding a rope in his teeth for the boy to lead, and broke a tooth when the child fell.
鲁迅 gave it a new meaning in his 1932 poem 《
自嘲》:
俯首甘为孺子牛, "head bowed, I gladly serve as an ox for the children". Since then it has meant anyone who serves the people without complaint.
