Jūzjānī tells us that he added the geometrical, astronomical, and music sections to the Najāt and made a revision of the chapter on arithmetic in Ibn Sīnā's Kitāb al-Shifāʾ that he prepared for the Najāt. Here is what he states in the introduction to the mathematics section of the Najāt (Ẓāhiriyya MS 9152, 1a-2b): The Shaykh al-Ḥakīm Abū ʿUbayd ʿAbd al-Wāḥid b. Muḥammad al-Jūzjānī states: When in the employ of the Grand Master Abū ʿAlī al-Ḥusayn b. ʿAbdallāh b. Sīnā, may God’s mercy and favor be upon him, I was in charge of collecting his writings and obtaining his books and treatises since it was his habit to give away what he had written to those who asked for them and not to keep a copy of them for himself. Among his great works in philosophy after the Shifā’ was this book, the Najāt. He put in it what he intended of logic, natural philosophy, and theology, but he never had the leisure to put in it the mathematical [sciences] due to the pressures of his difficulties. So the work remained as a fragment. I had some books of his written on the mathematical sciences that were appropriate for it [the Najāt] namely: [1] his book on the elements of geometry, which was epitomized from the book of Euclid. In his opinion he provided enough so that whoever knew it and confirmed [grasped] it would be able to undertake understanding the Almagest; [2] his book “on the comprehensive [general] observations and the knowledge of the arrangement of the orbs” as an epitome of the Almagest; [3] his book “the epitome of the science of music.” I have therefore decided to add these treatises to this book in order that his writings be consistent with what he indicated in his introduction. Since I did not find anything of his concerning arithmetic that was similar to these treatises, I decided to epitomize his book on arithmetic into a treatise and I set it forth as a guide to the knowledge of music and the ratios used in it and I also added it to [the Najāt].