Rishi: Traditionally attributed within the Vājasaneyin transmission to the ritual seer-line (often left unspecified for such protective formulas in later indexing).
Devata: Āyus (Life) / Rakṣā (Protective power), implicitly; secondarily Prajāpati as the life-sustaining totality in Brāhmaṇa bandhu.
Chandas: Mixed/Anuṣṭubh-like cadence (as transmitted in VS prose-verse style; metrical classification varies by pada-count).
This boundary I establish for the living: let none other pass beyond this appointed limit. May they live a hundred autumns, many in number; and may they set the death that breaks in upon life within, as with a mountain-barrier.