The paper deals with the brief Ottoman Sufi treatise Asrār-nāma included in the 18th c. handwritten madjmūʻa (collection of works) kept at the Scientific Library of SPbU (call number Ms.O. 701). The traditional attribution of the work to the Naqshbandī shaykh ʻAbd Allāh Ilāhī (d. 1491) looks highly doubtful. The author of the treatise was under profound influence of Ibn al-ʻArabī’s “Unity of Being” (waḥdat al-wudjūd) doctrine, of which the work is a simplified presentation. Some details of the Sufi Path described in the treatise indicate that its author was also familiar with the teaching of the Khalwatiyya brotherhood. The article gives a general description of the manuscript, an outline of the contents of Asrār-nāma, as well as brief characteristics of the first three texts gathered in the madjmuʻa.