In Chapter 11, Poem 18 of Attar's Mokhtar Nameh, the poet employs the metaphor of the 'bird of the heart' (مرغ دل) to depict the soul's spiritual estrangement and its futile pursuit of the divine secret. The poem highlights the themes of existential sorrow and bewilderment, illustrating the heart as a bird that has fallen far from its original, heavenly nest. Despite its desperate fluttering and suffering, it remains unable to unravel the mystery or return to its source, reflecting the central Sufi concept of the transcendent and ultimately inaccessible nature of ultimate divine truth.