Sankaracarya's Vivekachudamani 468

प्रत्यगेकरसं पूर्णमनन्तं सर्वतोमुखम् ।

एकमेवाद्वयं ब्रह्म नेह नानास्ति किंचन ॥

pratyagekarasaṃ pūrṇamanantaṃ sarvatomukham |

ekamevādvayaṃ brahma neha nānāsti kiṃcana ||

(Sankaracarya's Vivekachudamani 468)

The Subject within all, Non-dual, homogeneous, endless, all-pervading, there is only the Brahman; one without a second; in It there is no duality whatsoever.

The wholesome of the whole material world is Supreme Personality of Godhead, Prahlāda Mahārāja says, “Although He is not seen, He can still be perceived. One who is intelligent can perceive the presence of the Supreme Lord everywhere.” How is this possible? During the daytime, even someone in a room can know that the sun is up. Because it is light in his room, he can understand that the sun is shining in the sky. Similarly, those who have received perfect knowledge in disciplic succession know that everything is an expansion of the energy of the Supreme Lord. Therefore they see the Lord everywhere. The Lord is endless and beginningless, There is no one second the entire cosmic manifestation exist without the Supreme Lord Narayana, There is no one other than the Lord himself.