When the Báb determined to leave Shiraz on pilgrimage to Mecca, he instructed Mullá Husayn to travel to Isfahan, Kashan, Qom, Tehran and Khorasan Province, spreading Bábism as he traveled. Nabil indicates that Mullá Husayn was displeased when Quddús, the 18th Letter of the Living, was chosen to accompany the Báb on his pilgrimage rather than himself. The Báb is recorded to have indicated that Mullá Husayn would discover an important secret in Tehran, and would be able to effectively defend Bábism against opposition in the other cities of his journey.
