The hostility of the Quraysh to the new faith increased in bitterness as they watched the increase in the numbers of its adherents. They realised that the triumph of the new teaching meant the destruction of the national religion and the national worship, and a loss of wealth and power to the guardians of the sacred Kaʻbah. Muḥammad himself was safe under the protection of Abū Ṭālib and the Banū Hāshim, who, though they had no sympathy for the doctrines their kinsman taught, yet with the strong clan-feeling peculiar to the Arabs, secured him from any attempt upon his life, though he was still exposed to continual insult and annoyance. But the poor who had no protector, and the slaves, had to endure the cruelest persecution, and were imprisoned and tortured in order to induce them to recant. It was at this time that Abū Bakr purchased the freedom of Bilāl, [18] an African slave, who was called by Muḥammad “the first-fruits of Abyssinia.” He had been cruelly tortured by being exposed, day after day, to the scorching rays of the sun, stretched out on his back, with an enormous stone on his stomach; here he was told he would have to stay until either he died or renounced Muḥammad and worshipped idols, to which he would reply only, “There is but one God, there is but one God.” Two persons died under the tortures they had to undergo. The constancy of a few gave way under the trial, but persecution served only to re-kindle the zeal of others. ʻAbd Allāh b. Masʻūd made bold to recite a passage of the Qurʼān within the precincts of the Kaʻbah itself,—an act of daring that none of the followers of Muḥammad had ventured upon before. The assembled Quraysh attacked him and smote him on the face, but it was some time before they compelled him to desist. He returned to his companions, prepared to bear witness to his faith in a similar manner on the next day, but they dissuaded him, saying, “This is enough for thee, since thou hast made them listen to what they hated to hear.” The virulence of the opposition of the Quraysh is probably the reason why in the fourth year of his mission Muḥammad took up his residence in the house of al-Arqam, one of the early converts. It was in a central situation, much frequented by pilgrims and strangers, and here peaceably and without interruption he was able to preach the doctrines of Islam to all enquirers that came to him. Muḥammad’s stay in this house marks an important epoch in the propagation of Islam in Mecca, and many Muslims dated their conversion from the days when the Prophet preached in the house of al-Arqam.