The mathematical tradition that developed in North Africa during the Middle Ages continued to attract the interest of scholars in subsequent centuries. Medieval treatises were extensively read and made the subject of commentaries. In many cases, these commentaries became the object of other works—or supercommentaries—aimed at further clarifying the subject of the original treatises. This manuscript is an example of this phenomenon. In the 12th century, the North African mathematician ‘Abdallāh ibn Hajjāj ibn al-Yāsamīn summarized his mathematical knowledge in a versified treatise known as Yāsamīnīyya (The treatise by al-Yāsamīn). Around the end of the 15th century, al-Yāsamīn’s verses were the object of a prose commentary, Lum‘a al-Mardinīyya fī Šarh al-Yāsamīnīyya (The shimmer of al-Mardinī in the explanation of the treatise by al-Yāsamīn), by Muhammad ibn Muhammad ibn Ahmad Abū ‘Abdallāh Badr al-Dīn, also known as Sibt al-Mārdīnī. His main contribution was the description of the periodicity of sexagesimal fractions. Interest in this treatise was still alive in the 18th century, when the supercommentary preserved in this manuscript appeared. Its author, Muhammad ibn Sālim al-Hifnī, was born in 1689–90 into a very humble family in the Egyptian province of Šarqiyya. He moved to Cairo in his early teens, where he worked as a copyist of manuscripts, until a benefactor enabled him to completely devote himself to religious and juridical studies. His career as a jurist of the Šāfī‘ī school and as an active member of the Sufi order of the Khalwatiyya led him to one of the most prestigious intellectual positions in the Islamic world: he was appointed head of Al-Azhar University in Cairo in 1757 and continued in this role until his death in 1767–68.