Chapter 23, Part 5A - Chuang Tzu

Nan-jung Chu asked to be allowed to repair to his quarters. There he tried to cultivate his good qualities and rid himself of his bad ones; and after ten days of making himself miserable, he went to see Lao Tzu again.

Lao Tzu said, "You have been very diligent in your washing and purifying - as I can see from your scrubbed and shining look. But there is still something smoldering away inside you - it would seem that there are bad things there yet. When outside things trip you up and you can't snare and seize them, then bar the inside gate. When inside things trip you up and you can't bind and seize them, then bar the outside gate.

"If both outside and inside things trip you up, then even the Way and its virtue themselves can't keep you going - much less one who is a mere follower of the Way in his actions."
~ Burton Watson translation via Terebess Asia Online ~

Go here to read the introductory post to the chapters of the Book of Chuang Tzu.