Book 7: 《述而》 Shu Er (Transmission)
《述而》 Passage 7.8
子曰：「不憤不啟，不悱不發，舉一隅不以三隅反，則不復也。」
Legge Translation (1861)
The Master said: "I do not open up the truth to one who is not eager to get knowledge, nor help out any one who is not anxious to explain himself. When I have presented one corner of a subject to any one, and he cannot from it learn the other three, I do not repeat my lesson."