Śvetāśvatara Upaniṣad · 4..6
आत्मैवेदं सर्वम् तदन्यदपरं निरुक्तमवोचत् तद्वा एतद्विदित्वा योऽसावधोक्षजं विष्णुं महित्वे स्वर्गे पश्यति स सर्वेषु भूतेषु वसन्
ātmaivedaṃ sarvam tadanyadaparaṃ niruktamavocat tadvā etadviditvā yo'sāvadhokṣajaṃ viṣṇuṃ mahitve svarge paśyati sa sarveṣu bhūteṣu vasan
The Ātman is all this. That is the other, the distant —thus declared Nirukta. Knowing this, he who sees Viṣṇu, the Adhokṣaja, in the greatness of heaven, he dwells in all beings.
Absolute identity: ātmaiva idaṃ sarvam —the Ātman is all this. Nirukta (a Vedic text of etymology) declared that the “other” and “distant” is really the same. Adhokṣaja (Viṣṇu) is the one who cannot be sacrificed/penetrated by the senses. In our yoga practice, to see Viṣṇu “in the greatness of heaven” is to see the Ātman in infinite expansion. And the result: “dwells in all beings” —not as visitor but as the essence of all. To know this is to dwell in all simultaneously.