[Advaita-l] atman and saakshin

[Michael Shepherd]

Students can be unclear about the relationship between atman as the
'detached' aspect of Brahman yet actor in all things,, and saakshin as the
self's perfect witness of all, to be recognised and stayed with when it acts
in conjunction with antahkarana.

Can anyone point me to shastra discussion ot atman in relation to saakshin ?
It is such a practical aspect of Advaita. There are individual references
throughout the Vedanta, but I wondered if there were a key exposition.

Michael