This epistle introduces the reader to the Sunnah or "wont" of the Prophet Muḥammad, blessings and peace be upon him. By emulating, both in word and action, the wisdom-practice of the Prophet which preserved in writing every aspect of his conduct in every situation in life, the life and person of the believing Muslim acquire great blessedness and are able to achieve perfect harmony in both their spiritual and their material dimensions. This epistle brings the Prophetic Sunnah's spiritual courtesies and pearls of wisdom to light, treats the well-known but little-understood phenomenon of bidʿah or "religious innovation", and guides the reader in his exploration of subtle aspects of the emulation of the Most Beloved of Allāh. Although only about fifteen pages long (in its original Ottoman Turkish print), its reality, according to its author, is of a profound sublimity greater than that of the vastest oceans, and a power that outshines the lights of the greatest stars. This classic epistle, a "jewel-like criterion", provides the reader with an ascending stairway to the Sunnah and an antidote to the sickness of innovation in religion.