Introducing the Manuscript of Reality of Certainty by Astarabadi and its stylistic Manner

“Reality of Certainty” (Haq al-Yaqin) is one of the most famous works of Astarabadi (d. 1316), in which includes the principles of religion in addition to moral issues and has been categorized in the mystical literature of the Qajar era. The importance of “Reality of Certainty” as a manuscript is due to the fact that only one unique version is available. It is hoped that this research will pave the way for further research for the author, who, in addition to being a high-ranking religious official, is one of the great scholars in the field of meaning and mysticism. Considering that the mentioned book has not been corrected yet, its introduction may identify another literary figure in the thirteenth century. The author of the present research initially introduces the manuscript of "Haq al-Yaqin" and its calligraphic features and follows by introducing stylistic features of this work in three linguistic, intellectual and rhetorical structures.