The Dialogue of the Gulshan-i-Raz is a Persian Sufi mystical text that has been associated in various English translations with Omar Khayyam (c. 1048-1131), the Persian polymath who is best known in the English-speaking world as the author of the quatrains that Edward FitzGerald translated as the Rubaiyat of Omar Khayyam in the 1859 English version.
The Gulshan-i-Raz, meaning Rose Garden of Mystery, is actually the work of the fourteenth-century Persian Sufi poet Mahmud Shabistari rather than Khayyam himself. Various English editions have grouped the work with Khayyam material because of the shared Persian mystical tradition. The text is a dialogue in verse on the major questions of Sufi metaphysics, including the nature of being, the soul, knowledge, and the union of the self with the divine.
For readers interested in classical Persian Sufi literature in English translation, the Gulshan-i-Raz is a central document of the tradition.