Bhagavad Gita Chapter 9, Verse 4

मया ततमिदं सर्वं जगदव्यक्तमूर्तिना | मत्स्थानि सर्वभूतानि न चाहं तेष्ववस्थितः ||

mayā tatam idaṁ sarvaṁ jagad avyakta-mūrtinā mat-sthāni sarva-bhūtāni na cāhaṁ teṣv avasthitaḥ

By Me, in My unmanifest form, this entire universe is pervaded. All beings are situated in Me, but I am not situated in them.

Krishna reveals His supreme nature: 'Maya tatam idam sarvam jagad avyakta-murtina'—by Me (maya), in My unmanifest form (avyakta-murtina), this entire universe (idam sarvam jagad) is pervaded (tatam). 'Mat-sthani sarva-bhutani'—all beings (sarva-bhutani) are situated in Me (mat-sthani). 'Na ca aham teshu avasthitah'—but I (aham) am not (na ca) situated (avasthitah) in them (teshu). This is the paradox of the Supreme: He pervades everything, yet transcends everything. All beings exist in Him, but He is not limited by them. He is the foundation, the support, the source—yet He remains transcendent. This is the nature of the Supreme: all-pervading yet beyond all limitation.