Kitab al-Jami' (The Comprehensive Book)

Ibadi Islam's own account of how its scholarship formed runs through three names in sequence. Jabir ibn Zayd, the school's founding figure, was active in Basra in the seventh century. His student Abu Ubayda Muslim ibn Abi Karima carried the teaching forward after him, and Abu Ubayda's own student, al-Rabi ibn Habib al-Farahidi, produced the eighth century compilation that became the Musnad bearing his name, the hadith collection still used by Ibadi communities in Oman and North Africa today. That line settled which prophetic reports the school would treat as authoritative, and it did so early, within roughly two generations of Jabir ibn Zayd himself.

What that line did not yet do was build a developed legal method out of those reports. That came about two centuries later, in Oman, from a different kind of scholar working a different kind of problem, not what the Prophet's companions had said, which was already settled, but how a jurist should reason from what they had said to a ruling on a new question. Abd Allah ibn Muhammad ibn Baraka al-Bahlawi, an Omani jurist who died in the late tenth century, wrote the book that did this, Kitab al-Jami', alongside a contemporary, al-Kudami, whose own al-Mu'tabar covered similar ground. Ibn Baraka's contribution was to make prophetic tradition itself the stated foundation of both jurisprudence and scriptural interpretation together, giving Omani Ibadi law a systematic method rather than only a settled source. The hadith and the method arrived two centuries apart, from two different kinds of scholarship doing two different jobs.

Kitab al-Jami' takes its place at a specific moment in Ibadi Oman's legal history, one modern scholarship reads as the point where the school's jurisprudence matured from inherited hadith into a working legal system. Ibn Baraka wrote in the tenth century, roughly two hundred years after al-Rabi ibn Habib had already fixed the school's hadith corpus, and something like a century and a half before the later classical compendia, such as the nineteen volume Bayan al-Shar' produced by Muhammad ibn Ibrahim al-Kindi, that went on to build directly on Ibn Baraka's own foundation.

His achievement was methodological rather than narrative. Where the Musnad preserves what earlier authorities said, Kitab al-Jami' argues for how a jurist should reason from that inheritance to new rulings, treating prophetic tradition as the shared foundation of law and of scriptural interpretation alike. That distinction, between a school's source material and its method for using it, is not a minor technical point. Ibadi fiqh remains a living legal tradition in Oman rather than a historical curiosity, still drawn on today in matters of personal status alongside the country's general civil law, and the systematic method Ibn Baraka helped establish in the tenth century is part of why that continuity was possible. A hadith collection alone, however authoritative, does not by itself supply the reasoning a court needs; that had to be built separately, and Kitab al-Jami' is where Omani Ibadism built it.