This dissertation helps us understand how the ḥadīth teacher Ibn Ḥanbal (d. 855 C.E.) sought to resolve difficult legal problems that arose from Muslim and Christian coexistence. The arguments presented are based on a legal work titled Non-Muslim Religious Communities (NMRC), an early Ḥanbalī question-and-answer (masāʾil) text compiled by Abū Bakr al-Khallāl (d. 923), a second-generation student of Ibn Ḥanbal, which many historians of the Middle East have seen as indicative of quotidian social reality; that is, it tells us something about Christians and their interactions with Muslims. My goal in this dissertation, by contrast, is to show that legal discussions about Christians—and other non-Muslims—tell us something about Muslims: Christians are interpretive devices and hermeneutical subjects in arguments that shed light on Muslim concepts of identity, theology, and legal authority. A close reading of NMRC's discussion of contracts, women, children, and divorce oaths (īlāʾ, ẓihār, and liʿān) will substantiate this contention. This approach to legal hermeneutics might profitably be applied to other legal teachers and schools of law in the premodern period.