Although scholars have long studied how Muslims authenticated and transmitted Muhammad's sayings and practices (hadith), the story of how they interpreted and reinterpreted the meanings of hadith over the past millennium has yet to be told. Joel Blecher takes up this charge, illuminating the rich social and intellectual history of hadith commentary at three critical moments: classical Andalusia, medieval Egypt, and modern India. Weaving together tales of public debates, high court rivalries, and colonial politics with analyses of contemporary field notes and fine-grained arguments adorning the margins of manuscripts, Said the Prophet of God offers new avenues for the study of religion, history, anthropology, and law.