Zen - original face

Zen students should devote themselves at the beginning to zazen (sitting in meditation). Sitting in either the fully locked position or the half-locked position, with the eyes half-shut, see the original face that was before father or mother was born. This means to see the state before the parents were born, before heaven and earth were parted, before you received human form. What is called the original face will appear. The original face is something without color or form, like the empty sky in whose clarity there is not form.
      The original face is really nameless, but it is indicated by such terms as original face, the Lord, the buddha-nature, and the true Buddha. It is as with man, who has no name at birth, but afterwards various names are attached to him. The seventeen hundred koan or themes to which Zen students devote themselves are all only for making them see their original face. The World honoured One sat in meditation in the snowy mountains for six years, then saw the morning star and was enlightened, and this was seeing his original face. . . .
      Every time a thought arises, throw it away. . . . The thoughts are like clouds; when the clouds have cleared, the moon appears. The moon of eternal truth is the original face.

-DAITO (1282-1334), A FIRST ZEN READER