Shvetashvatara Upanishad Verse 6.11
Sanskrit
एको देवः सर्वभूतेषु गूढः सर्वव्यापी सर्वभूतान्तरात्मा। कर्माध्यक्षः सर्वभूताधिवासः साक्षी चेता केवलो निर्गुणश्च॥ ११॥
Transliteration
eko devaḥ sarvabhūteṣu gūḍhaḥ sarvavyāpī sarvabhūtāntarātmā | karmādhyakṣaḥ sarvabhūtādhivāsaḥ sākṣī cetā kevalo nirguṇaśca || 11 ||
Translation
There is one Divine Being hidden in all beings, pervading everywhere, the inner soul of all beings, the overseer of all actions, the indweller of all beings, the witness, the bestower of consciousness, unique and beyond all qualities.

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