What does the text say about the all-pervading cosmic principle, and what causes a deluded soul to perceive it as something separate from oneself?

As described in Chapter 37, there is a single principle that pervades everything from the creator (Brahma) down to the smallest blade of grass, in all moving and non-moving things. This principle, Brahman, is the same here and in the hereafter. However, for a soul deluded by ignorance, this reality is obscured. The text clarifies that when this quality-less principle is combined with adjuncts (upadhis), it appears as if it were not Brahman. This delusion is further cemented by the thought 'Parabrahman is different from me,' which keeps the soul subject to the cycle of death.