In this allegory from Attar's Mosibat Nameh, a mystic (bidil) is owed money but faces great difficulty collecting the debt. When advised by a dervish to defer the claim to the Day of Resurrection, the mystic explains that he will not be able to collect it then. He reasons that once they both escape the 'cage' of the material world, the duality between creditor and debtor will disappear, and they will simply be one. This parable illustrates the Sufi concept of ultimate unity (Tawhid), where individual identities and worldly disputes dissolve in the divine reality.