Istidlāl of Ibn al-Qassār by Istishāb in His Book Uyūn al-Adillah: From the Book of Al-Ḥajr and Bankruptcy to the End of the Book

This research examines the principle of continuity (istishab) as used by Ibn al-Qassar in his book, *Uyun al-Adillah*, due to his frequent use of it. The research begins with a brief biography of Ibn al-Qassar, followed by an exploration of the scholarly significance of *Uyun al-Adillah*. It then presents some definitions of continuity according to the four schools of Islamic jurisprudence (majhul), the types of continuity as presented by the author, and its applications in his book, *Kitab al-Hajr wa al-Taflis* (The Book of Guardianship and Bankruptcy), and so on. The research extracts examples of Ibn al-Qassar's use of each type of continuity in his arguments within these books, drawn from *Uyun al-Adillah*. Regarding the agreed-upon types of continuity, the first section examines two issues, and the second section examines three. For the disputed types, the first section examines three issues, while Ibn al-Qassar does not use this principle in the second section. The research concludes with key findings and recommendations.