In Poem 32 of Attar's Mokhtar Nameh, the 'bird of the heart' (مرغ دل) symbolizes the spiritual seeker's innermost essence. Through extensive spiritual flight and exploration, this bird uncovers infinite cosmic secrets ('worlds upon worlds'). Ultimately, the poem illustrates the profound Sufi realization of Tawhid (Divine Unity) by describing how the bird brings the vastness of 'both worlds' back into a single, unified point. This represents the mystical understanding that all multiplicity and dualities ultimately resolve into the One.