This book presents Imam Abdulrahman al-Bannani's significant supercommentary (Hashiya) on Jalal al-Din al-Mahalli's renowned explanation (Sharh) of Taj al-Din al-Subki's foundational text in Usul al-Fiqh, "Jam' al-Jawami'". Al-Bannani's work clarifies intricate points, resolves ambiguities, and expands upon al-Mahalli's interpretations, making complex legal theory more accessible. Additionally, the margins feature the valuable "Taqrir" (report/notes) by Sheikh al-Islam Abd al-Rahman al-Shirbini, offering further insights and scholarly discourse. This layered academic work is an indispensable resource for students and scholars of Islamic jurisprudence, representing a pinnacle of traditional Islamic scholarship in legal methodology.