The state of jurisprudence in the Maghreb during the Almoravid era, with its immersion in secondary issues, distanced it from the fundamentals and rendered it incapable of playing its role in reform. The call of Al-Mahdi, based on the fundamentals of jurisprudence and referring them back to their legal evidence, made them play their required educational role. In order to practically implement this reform, Al-Mahdi first and foremost took care of the two fundamentals of Sharia, the Quran and Hadith. He studied them in the East under great scholars such as Al-Kiya Al-Harasi, from whom he read Tafsir and Hadith, and Al-Mubarak bin Abd al-Jabbar, from whom he read Hadith, and Al-Tartusi, from whom he read Tafsir. Upon his return to the Maghreb, he began teaching these two fundamentals and made them the basis of the educational aspect of his call, urging his students to memorize verses and Hadith related mostly to worship or jihad, in addition to those related to the creed of monotheism. He also dedicated himself to writing about them, especially Hadith, in order to spread them further and for people to adopt them. He wrote a summary of Al-Muwatta, a summary of Sahih Muslim, and several treatises in which he arranged Hadith in a jurisprudential order. Alongside this direct teaching of the two fundamentals, he constantly referred to them in what he decided of meanings, frequently citing verses and Hadith, which often served as his starting point in building his ideas, whether in his correspondence, sermons, or writings. Thus, the tendency towards establishing fundamentals was evident in all his intellectual and educational activity, and it represented the core of that activity. This emphasis on fundamentals was most apparent in the jurisprudential writings left by Al-Mahdi.