I acknowledge this graphic from the Net
In this 137 verse and 111 dharana of Vigyana Bhairava Tantra, Shiva says,
Knowledge reveals through the Knower
Knowledge and Knower are together
Contemplate and move to Shiva space
In the 14th chapter of Bhagavad Gita, Krishna explains to Arjuna the concept on non duality in a very similar context. The chapter is called the Yoga of Kshetra and Kshetragna, the Union of Mind Body and Consciousness. When the mind body becomes aware of its underlying consciousness, the Sat Chit Ananda, it becomes one with that consciousness and all duality disappears.
Adi Shankara’s Atma Shatakam is about this verse. At the age of eight, when Shankara set out as a sanyasi from Kaladi in Kerala traveling north, he came to the Narmada river in spate. Wishing to cross the river, he set his kamandalu, the water pot at the edge of the river and prayed to the river goddess to allow him to cross. The river emptied herself in Shankara’s kamandalu to allow the child to cross. At the far end of the river, Sage Govinda Pada watched this scene in amazement. As the child Shankara approached him, Govinda Pada asked him, ‘Child. who are you?’ In Atma Shatakam or Nirvana Shatakam, as it is also called, Shankara negates his connection with his mind and body and announces himself to be Shiva, Sat Chit Ananda.
In a poignant fourth verse of these six verse Shankara says,
I am not related to sins or merit, pain or pleasure
I am not related to sacred chants or pilgrimage, the scriptures or sacrifices,
I am not the object of enjoyment, process of enjoying, or the person who enjoys
I am the Conscious Blissful form of Shiva
Substitute enjoyment with the word knowledge and Krishna appears in place of Shiva. By negating that he is the object of knowledge, the process of knowing and the person who knows, Shankara elevates himself to a level where these three combine. Knowledge, the object and process, merge with the subject of knower. there is no duality between the one who knows and what is known.
Ordinarily, this makes little sense. So what? What if I am the knower and also the knowledge. Think and you will know the difference.
Everything that is to be known is within you, not outside. This is today proven scientifically. Our mind has the code of all the languages of the world. It has the memory of everything that has happened since the inception of the world. This knowledge is within the knower, and yet the knower does not know! It is not so what, but so how or show how!
Go inwards to know all that exists outwards, said our sages. To be able to do that, we need to do this. Remove all conditioning of the past that create judgment and ego in us, which produce mind maps creating the separation between the knower and knowledge. To sustain this, disengage from all that happens within and without. Just be the witness or the observer. By disengaging from what happens outside, we also disengage from dualities of good and evil, right and wrong, fair and unfair, pain and pleasure etc. The non dual state is the ultimate reality of Sat Chit Ananda, state of Shiva.