Its full title is _Ri`áyat li-ḥuqúq Allah_, “The observance of what is due to God.” Footnote 68: This reading is given in the _Ṭabaqát al-Ṣúfiyya_ of Abú `Abd al-Raḥmán al-Sulamí (British Museum MS., Add. 18,520, f. 13_a_). 14. ABÚ SULAYMÁN DÁWUD B. NUṢAYR AL-ṬÁ´Í. He was a pupil of Abú Ḥanífa and a contemporary of Fuḍayl and Ibráhím b. Adham. In Ṣúfiism he was a disciple of Ḥabíb Rá`í. He was deeply versed in all the sciences and unrivalled in jurisprudence (_fiqh_); but he went into seclusion and turned his back on authority, and took the path of asceticism and piety. It is related that he said to one of his disciples: “If thou desirest welfare, bid farewell to this world, and if thou desirest grace (_karámat_), pronounce the _takbír_[69] over the next world,” i.e. both these are places of veiling (places which prevent thee from seeing God). Every kind of tranquillity (_farághat_) depends on these two counsels. Whoever would be tranquil in body, let him turn his back on this world; and whoever would be tranquil in heart, let him clear his heart of all desire for the next world. It is a well-known story that Dáwud used constantly to associate with Muḥammad b. al-Ḥasan,[70] but would never receive the Cadi Abú Yúsuf. On being asked why he honoured one of these eminent divines but refused to admit the other to his presence, he replied that Muḥammad b. al-Ḥasan had become a theologian after being rich and wealthy, and theology was the cause of his religious advancement and worldly abasement, whereas Abú Yúsuf had become a theologian after being poor and despised, and had made theology the means of gaining wealth and power. It is related that Ma`rúf Karkhí said: “I never saw anyone who held worldly goods in less account than Dáwud Ṭá´í; the world and its people had no value whatsoever in his eyes, and he used to regard dervishes (_fuqará_) as perfect although they were corrupt.” Footnote 69: The _takbír_, i.e. the words _Allah akbar_, “God is most great,” is pronounced four times in Moslem funeral prayers. Footnote 70: Muḥammad b. al-Ḥasan and Abú Yúsuf were celebrated lawyers of the Ḥanafite school. See Brockelmann, i, 171. 15. ABU ´L-ḤASAN SARÍ B. MUGHALLIS AL-SAQAṬÍ.