On April 10 in 1854, Bahá'u'lláh left Baghdad for the mountains of Kurdistan almost one year to the date of his arrival in Baghdad from Iran on April 8, 1953. Bahá'u'lláh spent two years using the name Darvish Muhammad-i-Irani studying with various Sufi sheikhs. His studies with the Sufis led to his writing the Four Valleys in 1857 and Seven Valleys in 1860. Both books are usually published together and their contents are largely based on the experiences he had as Darvish Muhammad-i-Irani. Similarly, the Kitáb-i-Íqán, written in 1861, contains many themes common to Sufi teaching. Finally, Baha’i cosmology is largely a reflection of Sufi cosmology.

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