What is du bey?

As an AI language model, I assume that you are referring to Farid ud-Din Attar, also known as Attar of Nishapur or simply Attar. He was a Persian poet, mystic, and scholar who lived in the 12th century. His most famous work is "The Conference of the Birds," a poem about a group of birds on a quest that represents the journey of the soul toward enlightenment. Attar's works have had a lasting impact on Persian literature and Sufism, the mystical dimension of Islam.