When a wise man has withdrawn his mind
from all things without, and when
his spirit has peacefully left all inner sensations'
let him rest in peace, free from the movement of will and desire. ...
For it has been said:
There is something beyond our mind
which abides in silence within our mind.
It is the supreme mystery beyond thought.
Let one's mind and subtle spirit rest upon that and nothing else.

When the mind is silent, beyond weakness and distraction,
then it can enter into a world which is far beyond the mind:
the supreme Destination. ...
Then one knows the joy of Eternity.

~ Maitri Upanishad, VI.19-23