By whose existence others exist and sustain after taking birth is Brahman.
In whom every being merges after death is Brahman. (Taitiriya Upanishad)
O Arjuna! I’m the soul living in the heart of all beings. (Gita 10:27)
The indestructible, transcendental living entity is called Brahman; and its eternal nature is call adhyatma, the self. (Gita 8:3)
Whatever is there in this universe is the Absolute Brahman. Use and utilize them with discretion and by not getting attached to them. (Ishavasya Upanishad)
Brahman very is this immortal Being.
In front is Brahman, behind is Brahman
To the right and to the left.
It spreads forth above and below.
Verily, Brahman is this effulgent universe. (Mundaka Upanishad)
Beyond, time, beyond space,
Thou art he from whom sprang
The three worlds.
Filled with Brahman are the things we see;
Filled with Brahman floweth all that is; (Svetasvatara Upanishad)