Abstract It is often said that the Shafiʿi school of law was the main source of the Malay-Indonesian Islamic legal tradition and codes during the last couple of centuries. However, one may wonder if further Islamic legal schools were welcomed in the archipelago and, if so, how and under what circumstances. On this subject, the author examines a rare, thick, fragile, and rare Persian manuscript. Copied in the seventeenth century, the manuscript in question is a work that was not only in the possession of Malay-speaking people. The manuscript clearly shows an attempt to translate it into local languages and to expand its jurisprudential clauses. Being a comprehensive source for the study and practice of Islamic law, it includes both Sunni and Shiʿi classical legal treatises, their Qurʾanic commentaries on “legal verses,” and relevant theological comments. This source has the potential to invite scholars to re-examine the context of seventeenth and eighteenth-century Southeast Asian manuscripts which used to be known as the turning point towards “Shariatization” by means of Arabo-Sunni legal and theological treatises, and to raise a more robust conjecture about the cosmopolitan nature of the Indonesian archipelago.