Chapter 31, Part L - Chuang Tzu

Confucius once more bowed twice, straightened up, and said, "Now that I have succeeded in meeting you, it would seem as though Heaven has blessed me. If, Master, you would not consider it a disgrace for one like myself to enter the ranks of those who wait upon you, and to be taught by you in person, then may I be so bold as to inquire where your lodgings are? I would like to be allowed to go there, receive instruction, and at last learn the Great Way!"

The stranger replied, "I have heard it said, If it is someone you can go with, then go with him to the very end of the mysterious Way; but if it is someone you cannot go with, someone who does not understand the Way, then take care and have nothing to do with him - only then may you avoid danger to yourself. Keep working at it! Now I will leave you, I will leave you." So saying, he poled away in his boat, threading a path through the reeds.
~ Burton Watson translation via Terebess Asia Online ~

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