Lieh Tzu had Lao Shang for his teacher, and Po Kao Tzu for his friend. When he had fully mastered the system of these two philosophers, he rode home again on the wings of the wind.Go here to read the introductory post to the chapters of the Book of Lieh Tzu.
Yin Sheng heard of this, and became his disciple. He dwelt with Lieh Tzu for many months without Visiting his own home. While he was with him, he begged to be Initiated into his secret arts. Ten times he asked, and each time received no answer. Becoming impatient Yin Sheng announced his departure, but Lieh Tzu still gave no sign.
So Yin Sheng went away, but after many months his mind was still unsettled, so he returned and became his follower once more. Lieh Tzu said to him: 'Why this incessant going and coming?' Yin Shêng replied: 'Some time ago, I sought instruction from you, Sir, but you would not tell me anything. That made me vexed with you. But now I have got rid of that feeling, and so I have come again.'
Lieh Tzu said: 'Formerly, I used to think you were a man of penetration, and have you now fallen so low? Sit down, and I will tell you what I learned from my Master. After I had served him, and enjoyed the friendship of Po Kao, for the space of three years, my mind did not venture to reflect on right and my wrong, my lips did not venture to speak of profit and loss. Then, for the first time, my Master bestowed one glance upon me--and that was all.
'To be in reality entertaining the ideas of profit and loss, though without venturing to utter them, is a case of hiding one's resentment and harboring secret passions; hence a mere glance was vouchsafed.'
'At the end of five years a change had taken place; my mind was reflecting on right and wrong, and my lips were speaking of profit and loss. Then, for the first time, my Master relaxed his countenance and smiled.
~ Lionel Giles translation via Terebess Asia Online ~