In August 1919, a newly crowned king in Afghanistan named Amanullah Khan (1892-1960) launched an ambitious reform program with the goals of reordering his kingdom into a constitutional monarchy. In this paper I show that as Shah Amanullah sought to propel dramatic top-down social change in Afghanistan through law, he was at pains to stress his reforms were a legitimate interpretation of Islamic jurisprudence in light of modern conditions. As a case in point, this paper focuses on one of the only extant documents attributed to the pen of Shah Amanullah—four Friday sermons he delivered in the southern city of Qandahar, Afghanistan in autumn of 1925. As a window into one of the twentieth century’s first—and largely unexplored—examples of Islamic legal modernism in power, this paper approaches Afghanistan’s Nizamnama reforms through the chief architect’s own words. I argue that by means of carefully crafted sermons endorsing his “shari’ah-compliant” social and legal reforms, Shah Amanullah sought the ever-elusive goal of reconstituting Afghan society in a manner conducive to the efficient administration of a centralized, territorial nation-state, all the while hoisting the modernist and populist banner of an “Islamic rule of law” in Afghanistan.