How does Brahman, which is described as being beyond the senses, become something that we can perceive and meditate on?

Chapter 50 explains this transition from the imperceptible to the perceivable. The pure, unmanifest Brahman becomes 'qualified' (shabal) by Avidya, or ignorance. This qualification allows it to be named 'Sat' (Existence), making it expressible through language and 'graspable by the intellect.' The text states that it then enters the mind and takes a discernible form through the 'Omkar.' It is this expressible, Omkar-Brahman that one can meditate upon. The text further elaborates that from this expressible Brahman, the Unmanifest (Avyakta) emerges, which then gives rise to the Great Principle (Mahat-tattva), egoism, and eventually the entire created world. Thus, meditation on the Omkar-Brahman is a way to connect with the source of this manifestation.