Mullá Ḥusayn had one more way to know who the new prophet was, and he had not told the Báb about. Siyyid Káẓim had told Mullá Ḥusayn that the new prophet would write a book explaining the Surih of Joseph. Siyyid Káẓim had also said that the new prophet would do this without anyone asking him to. After the Báb told Mullá Ḥusayn that he was the new prophet, he wrote a book about the Surih of Joseph. The Báb called that book the Qayyúmu'l-Asmá'