। ॥ ३५२ ॥
In plain words
The Supreme Self: eternal, without a second, undivided, consciousness alone; the silent witness behind the intellect and the other faculties; neither simply existent nor non-existent, but beyond both; the very thing the word 'I' actually points to, once you look past the ego; the innermost of the inmost, one solid mass of everlasting bliss.
Close to the Sanskrit
The Supreme Self is of the singular form of eternal, non-dual, undivided consciousness; the witness of the intellect and so on; distinct from the existent and the non-existent; the object indicated by the notion of the word 'I'; the innermost, a mass of eternal bliss.