Shabkar Tsokdruk Rangdrol (1781-1851 CE) was a Tibetan lama and prolific writer.  He spent much of his life wandering, visiting sacred sites and mountain retreats.  The excerpt below on the nature of mind is taken from a composition called Flight of the Garuda.

Let your mind spontaneously relax and rest.
When left to itself, ordinary mind is fresh and naked.
If observed, it is a vivid clarity without anything to see,
A direct awareness, sharp and awake.
Possessing no existence, it is empty and pure,
A clear openness of non-dual luminosity and emptiness.

It is not permanent, since it does not exist at all.
It is not nothingness, since it is vividly clear and awake.
It is not oneness, since many things are cognised and known.
It is not plurality, since the many things known are inseparable in one taste.
It is not somewhere else; it is your own awareness itself.
The face of this Primordial Protector, dwelling in your heart,
Can be directly perceived in this very instant.
Never be separated from it, children of my heart!

If you want to find something greater than this in another place,
It’s like going off searching for footprints although the elephant is right there.
You may scan the entire three-thousand-fold universe,
But it is impossible that you will find more than the mere name of Buddha.