La Risāla dar taḥqīq-i Nawrūz di Ismāʿīl Khātūnābādī.

The Risāla dar taḥqīq-i Nawrūz by Sayyid Amīr Ismāʿīl Khātūnābādī Iṣfahānī is dedicated to the history of the Iranian festival of Nawrūz, to the exact way of calculating its occurrence in the various eras and to the legitimacy of its celebration from the Shiite religious point of view. Due to these content characteristics, the operetta falls into the genre of nawrūziyya, compositions on various subjects dedicated to the Iranian New Year. The author indicates the reason that prompted him to compose the work in a controversy that arose between the learned Shiite jurisprudence of his time (second half of the 18th century) regarding a question of religious orthopraxis. It was a matter of establishing what was the exact moment in which to commemorate the event of Ghadīr Khumm, when ‒ according to the Shiite tradition ‒ the Prophet Muḥammad would have indicated his cousin ʿAlī as his successor at the helm of the newborn Muslim community. In fact, in the author's time in Persia the commemoration of the events of Ghadīr Khumm was officially celebrated in Nawrūz coinciding with the beginning of the year of the Persian solar calendar on the first day of spring, as required by a solid and ancient Shiite tradition. This tradition, both popular and scriptural, maintains that the event of Ghadīr Khumm took place at Nawrūz, even if this coincidence can be seriously questioned on the basis of chronological calculation. Furthermore, there is also the problem posed by the historical existence in the past of various possibilities for calculating the Nawrūz, since the Nawrūz became a fixed seasonal festival connected with the vernal equinox only in the second half of the 11th century.