[577] Mâtemed Abáśí, son of Motavakel, was the fifteenth khalif of the Abbasides. He began to reign in the year of the Hejira 256, A. D. 869, and died in 279, A. D. 892. [578] Rás í, the son of Mukteder, was the twentieth khalif of the Abbasides. His reign began in the year of the Hejira 322, A. D. 933, and ended in 329, A. D. 940. The period included between the beginning of the reign of Mâtemed and the end of that of Rási, is seventy-one years, differing by two from the period above stated; the minor absence might have begun two years before Mâtemed’s reign. [579] See the preceding note 2, pp. 383. 384. [580] معصوم means “defended, preserved (by God); innocent, an infant;” it is the particular name given by the Imamíahs to the twelfth Imám, Muhammed, the Askerite, who, as was related in the foregoing note 1, p. 383, was in his infancy concealed in a grot, from which he never came forth again, and is still expected. It is an ideal Imám, believed by more than one sect, and the name of _Mâśum_ was applied to more than one individual, as will be seen hereafter. [581] The author uses here and elsewhere the word _khabr_, which answers to our _gospel_. [582] Hassan al Baśri was the son of an affranchised man, called Mulla Zaid ben Tabeth, and of a slave woman, belonging to Omm Salmath, one of Muhammed the prophet’s wives. Hassan acquired the reputation of the first scholastic theologian among the Muselmans. He is surnamed al Baśri, because his father was a slave in Maissan, a borough of the dependencies of Baśra, or Bassora, and because he kept his school in that town, where different sectaries often came to dispute with him. Wassel Eben Ata, his disciple, deviating from his opinions, became the chief of the Mâtazalahs (see note 1, p. 325). Hassan al Baśri had seen the khalif Osman, and Eben Abbas; on that account he quotes in his works what he had learned from them. He died in the year of the Hejira 110, A. D. 728, and left a work entitled _Hadis sherif_, containing a collection of the traditions which he knew relatively to each of the fifty-four _feridhat_, or “obligatory precepts,” of the Muselman law. [583] The sixth Imám, of whom hereafter more will be said.