स यथा सर्वासामपां समुद्र एकाय-न प्रेत्य संज्ञास्तीत्यरे ब्रवीमीति होवाच याज्ञवल्क्यः ॥ १३ ॥
In plain words
Just as the ocean is the one place where every river finally becomes one — [so it is with everything else, as the fuller passage explains] — 'after death, there is no separate awareness left. That is what I am telling you,' Yājñavalkya said.
Close to the Sanskrit
Just as the ocean is the single confluence of all the waters — [so with all the sense-organs] — 'after departing, there is no separate awareness — that, O one, is what I say,' thus said Yājñavalkya. [Note: the source text itself abridges a long passage here, quoting only its opening and closing words.]