az-Zubayr as his source of "living sunnah" (living tradition) for his guideline to pass verdicts for various matters, in accordance of his school of though method. The second source, the Al-Mudawwana, is the collaborator work of Mālik's longtime student, Ibn Qāsim and his mujtahid student, Sahnun. The Mudawwanah consists of the notes of Ibn Qāsim from his sessions of learning with Mālik and answers to legal questions raised by Saḥnūn in which Ibn Qāsim quotes from Mālik, and where no notes existed, his own legal reasoning based upon the principles he learned from Mālik. These two books, i.e. the Muwaṭṭah and Mudawwanah, along with other primary books taken from other prominent students of Mālik, would find their way into the Mukhtaṣar Khalīl, which would form the basis for the later Mālikī madhhab. Maliki school is most closely related to the Hanafi school, and the difference between them is more of a degree, rather than nature. However, unlike the Hanafi school, the Maliki school does not assign as much weight to analogy, but derives its rulings from pragmatism using the principles of istislah (public interest) wherever the Quran and Sahih Hadiths do not provide explicit guidance. Notable differences from other schools The Maliki school differs from the other Sunni schools of law most notably in the sources it uses for derivation of rulings. Like all Sunni schools of Sharia, the Maliki school uses the Qur'an as primary source, followed by the sayings, customs/traditions and practices of Muhammad, transmitted as hadiths. In the Mālikī school, said tradition includes not only what was recorded in hadiths, but also the legal rulings of the four rightly guided caliphs – especially Umar. Malik bin Anas himself also accepted binding consensus and analogical reasoning along with the majority of Sunni jurists, though with conditions. Consensus was only accepted as a valid source of law if it was drawn from the first generation of Muslims in general, or the first, second or third generations from Medina, while analogy was only accepted as valid as a last resort when an answer was not found in other sources. Notable Mālikīs Ibn Abd al-Hakam (d. 829), one of the Egyptian scholars who developed the Maliki school in Egypt Asbagh ibn al-Faraj (d. 840), Egyptian scholar Yahya al-Laithi (d. 848), Andalusian scholar, introduced the Maliki school in Al-Andalus Sahnun (AH 160/776–77 – AH 240/854–55), Sunnī jurist and author of the Mudawwanah,