金剛三昧經

Vajrasamādhi-sūtra

V. Approaching the Edge of Reality

When a man in singleness of thought abides in "chüeh-kuan",
he will clearly see into the buddha-nature,

of which we cannot say whether it exists or exists not,
and in which there is neither selfhood nor otherness.

He will also find that the nature is the same both in the masses and in the worthies.
He thus firmly holds the ground of the diamond-heart

and never moves away therefrom;
he is serene and not-doing,

and free from conceptual discrimination.
This is called "entrance by reason".

[ D.T. Suzuki ]

[ Robert E. Buswell ]

… one abides frozen in "attentive contemplation".
One contemplates according to truth that the buddha-nature is

neither existent nor nonexistent.
It is neither self nor others and is

no different in either ordinary person or sage.
One abides firmly without wavering

in the state of adamantine mind,
calm, quiet, inactive, and

free from discrimination.
This is called the "access of principle".