What is the 'Unmanifest' or 'causal body' and what is its relationship with ignorance?

The 'Unmanifest' (Avyakruta), as detailed in Chapter 50, is identified as the 'causal' (karana) body of the soul. It is described as being imbued with the reflection of consciousness and is the very cause of pure ignorance (Avidya). The text states explicitly that 'The ignorance of the Soul is the cause of this.' This causal body is formless and subtle, described as being neither with parts nor without parts. Its removal is not possible through ordinary means; it can only be dissolved through the supreme knowledge of the unity of Brahman and the Soul. Until this knowledge arises, the causal body persists, binding the soul.