In 1298/1881, the Iraqi scholar Nu'mān al-Alūsī published his Jalā' al-'aynayn fī muhākamat al-Ahmadayn, one of the most astute tracts to be written in defense of the fourteenth-century Hanbalī scholar, Ibn Taymiyya. This article attempts to read into the significance of Jalā' al-'aynayn by studying the life and educational environment of its author, the subject matter of the book, the format in which it appeared, and the circumstances of its publishing. There is little doubt that Jalā' al-'aynayn is a founding text in the emergence of modern Salafiyya in major Arab urban centers. Considering the contribution of the Wahhābī movement to the revival of Salafī Islam, one of the aims of this article is to look into the variant expressions of modern Salafiyya. An important aspect of the impact of Nu'mān al-Alūsī's work is related to the way he treated his subject matter, reconstituting the legacy of Ibn Taymiyya in the Muslims' imagination of their traditions. The other, was the publishing of Jalā' al-'aynayn in print. In the following decades, the ecology of Islamic culture would be transformed at a dramatic pace. But two things would not lose their value for the Salafī circles of modern Islam, the referential position of Ibn Taymiyya and the power of the printing-press.