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。」
Tsze-kung 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.'