Book 15: 《衛靈公》 Wei Ling Gong (Duke Ling of Wey)
《衛靈公》 Passage 15.24
子貢問曰：「有一言而可以終身行之者乎？」子曰：「其恕乎！己所不欲，勿施於人。」
Legge Translation (1861)
Zigong asked, saying: "Is there one word which may serve as a rule of practice for all one's life?"The Master said: "Is not RECIPROCITY such a word? What you do not want done to yourself, do not do to others."