There once lived a brilliant student. He was on a quest to acquire more and more knowledge. Then he heard of a great Zen teacher to whom he travelled long to meet.
On arriving at the teacher's feet, he said, "Master teach me." The Zen master received the student with a smile. He inquired about him. He asked in detail all that the student had learnt till then.
Later, he asked his assistant to get tea for the two of them. A big pot of tea with two cups and saucers was brought before the master. The student volunteered to serve the tea. The master brushed aside his offer with a smile.
He asked the student to lift up a cup and saucer so that he could serve him tea. The student lifted his cup and saucer. The master started pouring tea into his cup. The tea filled the cup. The master did not stop. He kept pouring the tea. It flowed out of the cup into the saucer. Still the master kept on pouring the tea. The student was surprised.
When the tea started overflowing the saucer too, the startled student said "Master, you are serving tea more than the cup can hold." Master smiled and stopped serving him tea.
He said, "Dear student, the same is the case with you. You have learned enough. Your knowledge is overflowing. Put this into practise rather than wanting to acquire more knowledge, which will go waste like this tea."
The student realized the importance of practising what is learnt and left the master a wiser man.