Ahmad Muhammad Shakir (1892-1958) was one of the most influential Egyptian Muslim scholars of the twentieth century. In addition to serving on the Shari'a supreme court and authoring a number of works on the modernization of Islamic law on such topics as divorce and the Muslim calendar, Shakir was a prolific editor, producing the first scholarly editions of numerous medieval works on law, Hadith, and the Arabic language. Shakir's editions played a significant role in the cultural rediscovery of these texts and their establishment as classical reference points in the construction of Muslim intellectual identity. This paper examines Shakir's editing projects as a window into the construction of a Muslim religious tradition by a modern and modernizing Muslim scholar. In the introduction to his partial edition of al-Tirmidhi's Sunan (Cairo, 1937), Shakir argues for the crucial importance of accurate editions for the reclaiming of the Muslim intellectual past. He emphasizes that such editions should be made by Muslims rather than Orientalists, as some of the latter, in his view, follow agendas that amount to intellectual colonialism. Shakir demands modern standards of critical edition, but argues that these standards were not invented by Europeans; rather, he claims that classical Muslim scholars had already developed similar standards in their works, as shown by the writings of scholars as far back as al-Jahiz (d. 869). Shakir’s groundbreaking edition of al-Shafi'i's Risala (Cairo, 1940) demonstrates the precision of a truly critical edition, and set the model for all subsequent editions in the Muslim world. Shakir's insistence that critical standards of editing were already present in medieval Muslim scholarship is connected to his substantial reformist agenda. By editing and publishing works that had fallen out of scholarly usage, such as Ibn Hazm's Muhalla (Cairo, 1929-1934) and al-Shafi'i's Risala, Shakir revived texts that he then used to challenge the legal institutions of his day, in particular the hegemonic schools of law (madhahib). In order to harness classical works for such a purpose, Shakir had to be able to rely on their textual integrity, which required the production of reliable editions from the still-extant individual copies. The tools of critical editing thus offered an alternative criterion of authenticity to replace the unbroken chain model of scholastic tradition, and thereby provided an alternative basis of religious authority.