Farid Ud-Din Attar - The Conference of the Birds.

"A man was always complaining about the bitterness of poverty, so Ibrahim Adham said to him: 'My son, perhaps you have not paid for your poverty?' 

The man replied: 'What you say is nonsense, how can one buy poverty?'

'I at least' said Adham 'have chosen it voluntarily and I have brought it at the price of the kingdom of the world."

Farid Ud-Din Attar - The Conference of the Birds.

Farid Ud-Din Attar was one of the earliest Sufi poets of Persia. Attar's best known work is called Mantiq-ut-Tair, or the 'Conference of the Birds'