The Ocean of Principles of Jurisprudence, 6 volumes

Author's name: Al-Zarkashi

Al-Zarkashi was a Shafi'i jurist and scholar of legal theory who gifted Muslims with great books on the principles of jurisprudence. This is his book, Al-Bahr fi al-Usul (The Sea in Principles), in which he mentioned that he compiled from the book Al-Usul al-Mi'in (The Hundred Principles), and he listed his references in the introduction of the book, which amounted to dozens of principles of the Shafi'i, Hanafi, Maliki, and Hanbali schools.
The Zahiri, Mu'tazili, and Shi'a schools of thought, and despite the abundance of his references, he mentioned that he added thousands of questions to what God had revealed to him, resulting in a book that compiled what was scattered in other works, attributing them to their authors and sometimes quoting them verbatim for affirmation or critique. It contains many definitions and questions, as he called it, "The Surrounding Sea."