Immovable.

The first of the four foundations of Dzogchen meditation is immovable. As a preparatory practice we want to settle the mind and be able to recognize and abide in the nature of mind. Having been introduced to the Dzogchen view, we can sustain that view and eliminate errors and deviation through the practice of the four foundations.

First, we rely on the three immovables.
Immovable body, like a mountain.
Immovable gaze, like a lion.
Immovable awareness, like the sky.

Immovable body, like a mountain. The body is relaxed and uncontrived, seated in the Vairocana posture. Don't chase after feelings or sensations, simply rest the body, breathing naturally. Don't itch, don't alter, don't adjust.

Immovable gaze, like a lion. Leave the sense organs open and uncontrived, free from grasping. The gaze is open, like looking over a vast mountain valley, but steady like a lion. A dog's gaze chases after everything that appears before it, hopping from one focus to another. We don't want to focus on any particular object or point, keep the gaze steady, but expansive, like your field of vision is the space around you.

Immovable awareness, like the sky. Whatever clouds or weather moves through the sky, the sky remains unstained. There is no good or bad, nothing to accept or reject, nothing to hold onto or push away. Relax in an uncontrived, open awareness free from thoughts or fabrication.

We can also describe the immovable state in terms of outer, inner and secret.

Outer is the body in the Vairocana posture.
Inner is uncontrived, without altering or chasing, without effort. Free from expectation, hope and fear.
Secret is kadag, original purity. Recognize the potency of rigpa arising from the ground of original purity and let everything dissolve back into the ground of original purity, free from any reaction or judgement.

Relying on the unique Dzogchen mindfulness we sustain the view of rigpa. Without being distracted by appearances or the internal display of mind, we simply rest in an experience of unceasing clarity.

As we gain greater stability in immovable state, we enter the single-pointed state.