The copies of the Talmud in Sora, which were now no longer used, were, later on, transferred to Spain. Babylonia, so long the center of Judaism, had to yield its supremacy in favor of a foreign place. The decay of one of the Babylonian schools, and the decline of interest that followed upon it, were utilized by the Karaites to make converts amongst the Rabbanites. They did this with such zeal that they thought they were about to strike the death-blow to Rabbanism. As long as Saadiah, the mighty champion of Rabbanism, lived, they did not venture to do anything to expose themselves to his criticism. But after his death, when they perceived that there was no man of any importance to stand in the breach, they hoped to obtain an easy victory. Saadiah's opponent, Solomon ben Yerucham, immediately hastened from Palestine to Babylonia, in order to prove to the followers of Saadiah, that he had misrepresented facts in his defense of the Talmudists. Thus he expected to bring over the Rabbanites to Karaism. But a more vehement, zealous and cunning proselytizer was Abulsari Sahal ben Mazliach Kohen, an inhabitant of Jerusalem, who belonged to the ascetic section of the Karaite community. Abulsari Sahal had a thorough knowledge of Arabic and Hebrew, and wrote in a much more elegant style than any of his contemporaries. He compiled a Hebrew grammar, commentaries to several books of the Bible, and also a compendium of religious duties under the title "Mizvoth." However, he did not write anything of great consequence. The Karaites seem to have had no ability to get beyond beginnings; certainly not Sahal, who was possessed by sombre, monkish piety. To his co-religionists, nevertheless, he appeared in the light of a great teacher. Sahal also wrote a refutation of Saadiah's attacks upon Karaism. It was, doubtless, considered an honorable thing amongst the Karaites, to win one's spurs in combat with this great champion. Sahal appears to have delivered his lectures against the Rabbanites in Bagdad. He called upon the people to renounce tradition, and to refuse obedience to the schools, "which were the two women of whom the prophet Zechariah speaks, and who carried sin and left it in Babylon." Sahal implored his hearers to renounce the indulgences that their Rabbanite teachers allowed them, such as keeping oil in camel-skins, purchasing bread from Christians and Mahometans, and leaving their houses on a Sabbath.