--The Aim--

A long time ago, Baso of Kiangsi Province was training under Zen Master Nangaku. While staying in Chuan-fa Temple, Baso had been doing seated meditation day in and day out for some ten years or more. 
One day when Nangaku came to Baso’s hut, Baso stood up to receive him. Nangaku asked him, “What have you been doing recently?”
Baso replied, “Recently I have been doing the practice of seated meditation exclusively.”
Nangaku asked, “And what is the aim of your meditation?”
Baso replied, “The aim of my seated meditation is to achieve Buddhahood.” 
Thereupon, Nangaku took a roof tile and began rubbing it on a rock near Baso’s hut.
Baso, upon seeing this, asked him, “Reverend Monk, what are you doing?”
Nangaku replied, “I am polishing a roof tile.”
Baso then asked, “What are you going to make by polishing a roof tile?”
Nangaku replied, “I am polishing it to make a mirror.”
Baso said, “How can you possibly make a mirror by rubbing a tile?”
Nangaku replied, “How can you possibly make yourself into a Buddha by doing meditation?”

----!!!!----

This story is taken from the book Shobogenzo, written by the great Zen Master Dogen! The book is written in Chinese(??). The translator says:
The translation may not clearly convey the contradiction in Baso’s statement. The particular practice of seated meditation he specifically mentions is 'chih-kuan ta-tsuo', a Chinese colloquial phrase that implies sitting in meditation without deliberately thinking of anything, or holding on to anything that naturally arises, or pushing away anything that naturally arises, and without trying to suppress any thoughts from arising. However, in reply to Nangaku’s question, Baso indicates that, in fact, he has something he is deliberately holding in his mind, namely, the goal of realizing Buddhahood, literally ‘making himself into a Buddha’!

Later on Dogen said:

        Polishing a tile to make a mirror is diligent effort.

        and

                               Polishing a tile to make a mirror is our reward for accumulating merit and virtue.

                              He also said:

        Instead of hitting the ox, you should hit the cart.

        and

        When one cart is hit, many carts go quickly.

Why the master is saying that instead of hitting the ox, one should hit the cart. One cannot know directly the ultimate truth. So one has to start meditating over the body and mind and then only he goes beyond.