In Chapter 11, Poem 28 of Attar's Mokhtar Nameh, the poet employs the metaphor of the kernel (مغز) and the shell (پوست) to illustrate the ultimate inaccessibility of the divine essence. The poem conveys that despite relentless effort—peeling back 'a thousand layers' of outward religious forms—human intellect and effort are left completely exhausted and unable to perceive the core truth. This concept underscores a major mystical theme: the limitations of formal religion and intellectual exertion in attaining direct knowledge of the divine reality.