The glorious mission entrusted to Mulla Husayn was truly enviable. Its nature was intimated to him by the Báb in assuring words:
"In this pilgrimage upon which We are soon to embark, We have chosen Quddus as Our companion. We have left you behind to face the onslaught of a fierce and relentless enemy. Rest assured, however, that a bounty unspeakably glorious shall be conferred upon you. Follow the course of your journey towards the north, and visit on your way Isfahan, Kashan, Qum, and Tihran. Beseech almighty Providence that He may graciously enable you to attain, in that capital [Tihran], the seat of true sovereignty. A secret lies hidden in that city. When made manifest, it shall turn the earth into paradise. My hope is that you may partake of its grace and recognize its splendour.”
When Mulla Husayn reached the capital, Tihran, he lived in one of the rooms of a religious school. The leader of the Shaykhi community of Tihran, who acted as an instructor in that institution was approached by Mulla Husayn but failed to respond to his motivation to accept the Message of the Báb. Mulla Husayn assured him that he had no intention of prolonging his stay in Tihran, that his aim was in no wise to abase or suppress the teachings inculcated by Shaykh Ahmad and Siyyid Kazim.
During his stay in that capital Mulla Husayn did not appear in public. He limited himself to confidential conversations with those who visited him. He received a fair number of individuals and won over a large number of enquirers. According to the French historian Comte de Gobineau, among the people who showed interest in seeing him were the King, Muhammad Shah and his Minister, Haji Mirza Aqasi. Mulla Husayn presented them with some of the Writings of the Báb.