Witnessing, as in the transcendental sense, is always different, from moment to moment. It is never the same.
There is no "THE" Witness. There is only WitnessING, one with and identical to the content of experience, at any moment.
Witnessing faces experience by means of attention, but also witnesses the intention of attention to locate, like a mouth as large as the sphere of our experiencing, all that emerges to experience in the Unknownably Unknown.
WitnessING : IS : IS : Witness.
"The" Witness is an anthropomorphic artifice, like The Bearded God or Santa Clause.
Witnessing is not a self. All selves are being Witnessed. We are being witnessed. "We" are not Witnessing.
So, to "be" The Witness is to intuit BEING Witnessed. If an "other" "doing the witnessing" appears, that is also being witnessed.
To be witnessed is not to be known or to be a subject of knowledge or memory. Witnessing is not recording anything.
To be witnessed is to be at the meeting place of the unknown and the known -- and that is all.
The Unknown Witnessing everything, is witnessing US. We are being witnessed. But not known.
We intuit being witnessed when we sense of things in particular. To the degree that we sense anything particular, to that degree are we being witnessed, witnessed doing the sensing -- witnessed, but not known. Witnessed : Illuminated for Attention
What is witnessing us is Unknowably Unknown -- Unknowably Unknown -|- right out through the top of the head.
The Unknowably Unknown IS the constancy of The Intuition of "THAT" --, "the same, throughout all my life, as now" -- most subtle, everpresent. NOT particular.
The Unknowably Unknown is unknowably unknown, now -|- from the heart region through the tongue to the palate, to the brain core, breathing in through the top of the head. Old Faithful.