आप एव यस्यायतनँ हृदयं लोकोमनोज्योतिर्यो वै तं पुरुषं विद्यात्सर्वस्या-त्मनः परायणँ स वै वेदिता स्यात् ।याज्ञवल्क्य वेद वा अहं तं पुरुषँ सर्व-स्यात्मनः परायणं यमात्थ य एवायमप्सुपुरुषः स एष वदैव शाकल्य तस्य कादेवतेति वरुण इति होवाच ॥ १६ ॥
In plain words
Waters are his home, the heart his world, the mind his light. Know that person and you have reached the final resting place of every self there is. I know him, says Yajnavalkya — the one who lives right there in the waters. That's him, Shakalya, standing before you. Ask on: what god does he answer to? Varuna, he says.
Close to the Sanskrit
'The waters alone are his abode', the heart his world, the mind his light — whoever should know that person as the final resort of the self of all, he would indeed be a knower. Yājñavalkya: I know that person, the final resort of the self of all, of whom you speak — the one who is this person in the waters. He is this very one, Śākalya; speak on! Of him, what is the deity? — 'Varuṇa', he said.