Beyond the world that changes and the self that watches stands the One who holds both up.

Read through Shankara and Madhusudana, as the third reality of pure consciousness.

Here the Highest Person is the heap of consciousness that lights up both of the other two without being reducible to either: the insentient perishable and the imperishable enjoyer are both, in their own way, still heaps belonging to ignorance's constructions. He is named the supreme Self because he stands above every self imagined in turn, made of food, of breath, of mind, of understanding, of bliss, ending only at the unimagined reality even those sheaths point toward. He upholds by the sheer fact of his own true being, and no labor enters into it at all.

Read through Ramanuja, as the real inner Self of a living triad.

Here the two prior persons are the bound soul and the freed soul, and 'the three worlds' opens into a triad you can know by valid means of knowledge: insentient matter, the soul joined to it, and the soul set free from it. The Highest Person enters this entire triad as its inner Self and upholds it in a relation that is real and lasting, never a manner of speaking. The one who upholds a thing must be other than the thing upheld, and by this very reasoning he stands apart from all three.

Flagged honestly as a thin source for this specific verse.

What survives here attributed to Madhva is only a brief note: this is the supreme Vishnu, beyond both the perishable and the imperishable. It is not a developed commentary in his own extended voice on this verse, and the fuller Dvaita reasoning about the exact sense of perishable, imperishable, and freedom from the net of transmigration belongs properly to the sub-commentary tradition on the surrounding verses, not to a paragraph authored here.

Flagged honestly as a thin source, with any fuller reading offered only as a conditional extension.

What survives here attributed to Abhinavagupta is likewise a single terse identification: this is the supreme spanda, the source of both the manifest and the unmanifest. On a Kashmir Shaiva reading, one might extend this to say that spanda, the living pulse of consciousness, underlies both the world of objects and the still witness-awareness as their shared source; but that extension is offered only for orientation, not as a report of Abhinavagupta's own extended words, since his surviving commentary here does not go further than the single identification.

Read through Sridhara, as the one who is neither object nor mere knower.

Here the two names given to the Highest Person, supreme and Self, do two separate jobs. By being Self, he is distinct from the perishable, which is unconscious matter. By being supreme, he is distinct from the imperishable, taken as the conscious enjoyer still bound within that matter. He is neither the perishing object nor the unchanging knower, but the one who, standing above both, holds both up.

Read through Madhusudana's graded ladder, as a map for self-inquiry.

Every layer of self you might name, the body, the breath, the moving mind, the sense of understanding, even a subtle contentment that can pass for peace, is still, on this reading, a self imagined by degrees of ignorance, not the final reality. The Highest Person is what remains when that ladder of self-description finally runs out: the inner consciousness of every being, present in the noticing itself rather than in anything noticed.