Mantiq al-tayr (the conference of the birds) is an elaborate allegory with many digressions. It describes how all the birds (human souls) set out in search of the Simurgh (the godhead). All but 30 die and the survivors realize that they themselves are the Simurgh.
Attar Books
This Persian poet, Sufi theoretician, and hagiographer, known by his pen name Farīd ud-Dīn 'Attār, exerted an immense and lasting influence on Persian poetry and Sufism. His writings often delve into profound spiritual themes, exploring the paths to enlightenment through mystical insight.

