By Zenmaster Han-shan De-qing (1546 – 1623), China. Coming from a poor family, he entered monastic life when he was eleven years old. Later he was the motor behind the revival of Zen practice in Ming China.

Looking at what your body is – it is not you
But an image in the mirror of awareness,
Just like the reflection of the moon on the water.

Looking at what your mind is – it is not
The thoughts and feelings that appear within it
But the bright knowing space that holds them.

When not a single thought arises, your mind is
Open, perceptive, serene and luminous;
It is complete as great all-embracing space
And holds all kinds of wondrous aspects.

Your mind does not come or go away,
Has no particular shape, nor a special way of being.
But a great many beneficial qualities
Come all forth from this one knowing being.

It does not depend on physical existence,
Physical existence covers it up!
Do (therefore) not take vain hopes seriously,
Vain hopes lead to illusory phenomena.

Closely investigate this ‘mind’, which is
Knowing emptiness, not containing a thing.
When you are suddenly flooded with emotions
Your vision gets unclear, your experience confused.

Then at once bring back your presence of mind
And gather all your strengths to reflect.
The clouds will disperse and the sky will clear:
The sun of awareness spreads brightly its light.

If no feelings or thoughts arise within
No (worrying) circumstance is found without.
So where lies the original reality
of all that has characteristics?

If you can be aware of a thought as it arises
This awareness dissolves the thought at once.
Sweep away whatever state of mind may come,
Be present and aware – and you will be free.

Good and evil, internal or external,
Transform when you turn towards the heart of it.
Worldly and spiritual forms
Come into being through what you think.

Using a mantra and looking at your mind
Are means to polish the mirror of awareness;
Once the obscurations have been removed
They have no more use and can be dropped.

All great and deep spiritual abilities
Are already complete within your mind
And you can roam as you wish
To the Pure Land or Heavenly Palace.

There is no need to search for Truth
As your mind is from the beginning already enlightened.
When your training is ripe, all things seem fresh and new,
When new and fresh in training,  this ripeness is inherently present.

Day and night all things are miraculous
And you will have faith in whatever you meet.

The above is what you need to know regarding the mind.