अथाधिभूतम् ।यः सर्वेषु भूतेषु तिष्ठन् सर्वेभ्यो भूतेभ्योऽन्तरो यं सर्वाणि भूतानि न विदुर्यस्य सर्वाणि भुतानि शरीरं यः सर्वाणि भूतान्यन्तरो यमयत्येष त आत्मान्तर्याम्यमृतः ।इत्यधिभूतम् ॥बृह. ३,७.१५ ॥
In plain words
Now with respect to beings. He who dwells in all beings, yet is within all beings, whom all beings do not know, whose body all beings are, who from within controls all beings — he is thy Self, the inner controller, the immortal. So much with respect to beings.
The commentators
Bṛhadāraṇyakopaniṣadbhāṣyam· bhāṣya
समानमन्यत् । योऽप्सु तिष्ठन्, अग्नौ, अन्तरिक्षे, वायौ, दिवि, आदित्ये, दिक्षु, चन्द्रतारके, आकाशे, यस्त- मस्यावरणात्मके बाह्ये तमसि, तेजसि तद्विपरीते प्रकाश- सामान्ये-- इत्येवमधिदैवतम् अन्तर्यामिविषयं दर्शनं देव- तासु । अथ अधिभूतं भूतेषु ब्रह्मादिस्तम्बपर्यन्तेषु अन्तर्या- मिदर्शनमधिभूतम् ॥
In plain words
The rest of the list runs the same way -- in water, in fire, in the space between earth and sky, in wind, in the heavens, in the sun, in every direction, in the moon and stars, in space itself. And darkness, which only ever covers something from outside, and light, its exact opposite, brightness in its most general form -- all of it is one teaching, given here in terms of the gods, about the one who governs from within. Now comes the same teaching told in terms of living things -- everything from Brahmā down to a single blade of grass.
Close to the Sanskrit
The rest is similar: he who dwells in the waters, in fire, in the intermediate region, in the wind, in heaven, in the sun, in the quarters, in the moon-and-stars, in space, and -- as for darkness, which has the nature of an external covering, and light, which is the opposite of that, the general form of illumination -- thus, in this way, is the teaching concerning the antaryāmin regarding the deities. Now, regarding beings: among beings from Brahmā down to a tuft of grass, the teaching concerning the antaryāmin is called adhibhūta.