Based on the teachings, what exactly is the 'Unmanifest' or 'Avyakruta' and how does it relate to the soul?

The 'Unmanifest,' also referred to as 'Avyakruta,' is identified as the causal (karana) body of the soul. According to the explanations in Chapter 50, this state is associated with the reflection of consciousness and is considered the very cause of pure ignorance, or 'Avidya'. The text describes it as something that is neither with parts nor without parts, nor a combination of both. Ultimately, the removal of this causal body, which is a crucial step toward liberation (Moksha), can only be achieved through gaining the profound knowledge of the unity between Brahman and the Soul.