Tsai Yu being asleep during the daytime, the Master said, "Rotten wood cannot be carved; a wall of dirty earth will not receive the trowel. This Yu, what is the use of my reproving him?"Go here to read the introductory post to this serialized version of the Analects of Confucius.
The Master said, "At first, my way with men was to hear their words, and give them credit for their conduct. Now my way is to hear their words, and look at their conduct. It is from Yu that I have learned to make this change."
~ James Legge translation via The Internet Classics Archive ~