Those who know Me together with My extensive material and divine manifestation (ādhibhūtā and adhidaiva), and also as the Lord of sacrifices (adhiyajña), will know Me well even at the time of leaving the body, united as they are always with Me.
To know Brahman or the Self is not merely to know the supreme Truth with any specific focus. The infinite world of matter and energy around us is all Brahman’s perceptible manifestation, called adhibhūta.
Adhidaiva is whatever is divine, Providential. The mysterious and invincible rhythm in the Universe hosting countless celestial bodies, each interconnected with the rest, can only be under a divine dispensation. Such a rhythm, inconceivable to human intellect, is divine indeed.
The third is adhiyajña, whereby every living organism seeks its food and nourishment from one source or another. Such food is digested, assimilated and absorbed to become hot circulating blood in the body, like the offerings made for various deities are consumed by fire.
Full knowledge of Brahman must include all these aspects.