sa yathemā nadyaḥ syandamānāḥ samudrāyaṇāḥ samudraṃ prāpyāstaṃ gacchanti bhidyete tāsāṃ nāmarūpe samudra ityevaṃ procyate | evamevāsya paridraṣṭurimāḥ ṣoḍaśa kalāḥ puruṣāyaṇāḥ puruṣaṃ prāpyāstaṃ gacchanti bhidyete cāsāṃ nāmarūpe puruṣa ityevaṃ procyate sa eṣo'kalo'mṛto bhavati tadeṣa ślokaḥ ||
""Just as these rivers, flowing toward the ocean, upon reaching the ocean disappear, their name and form being dissolved - they are simply called 'ocean' - so also these sixteen parts of the witnessing Person, flowing toward the Person, upon reaching the Person disappear, their name and form being dissolved - it is simply called 'Person.' That one becomes partless and immortal. On this, there is a verse:""
What This Means:
Rivers lose their names and forms when they merge into the ocean. Similarly, the sixteen parts dissolve into the Person, becoming partless and immortal.
Going Deeper:
This is the famous river-ocean metaphor for liberation. Individual distinctions merge into the infinite. Names and forms are temporary; the essence is eternal.
How To Apply This:
Like a river reaching the ocean, let your limited self merge into the infinite Self. In that merging is immortality.