The Prophet then ordered Bilal to call the Faithful to prayer. When the idolaters heard the resounding accents of the black freed slave, reverberating in the echoes of the valley, they were so deeply annoyed that they envied the fate of their illustrious dead, Abu Jabal and Abu Lahab, prevented from hearing this call by the weight of the earth piled on their graves. After the prayer, Mohammad again bestrode his she-camel, to perform the "Sa'y" which is the run between the two hills of Safa and Marwa. His example swept away the Believers' scruples; for until then, they had hesitated about going through this ceremony, being embarrassed by the presence of the idols Isaf and Na'ila, set up at that spot. By the performance of these rites, instituted by Abraham and perpetuated by the Arabs, the Prophet had in view a nationalist and political goal, which he wished to combine with his religious aims. If he kissed the Black Stone, it was not by reason of a feeling of superstitious worship which would have contradicted all the principles of the Qur'an much too flagrantly, but solely through a feeling of reverence for this relic of his glorious ancestor. Quoth Ibn Abi Shayba, following Isa ibn Talha: "Addressing the Black Stone, the Prophet declared: Verily, I know that thou art nothing more than a stone, powerless to do harm, or be of any use. Then he kissed it.... In this conjuncture, Abu Bakr, followed by Umar, one after the other, came and kissed it, declaring: By Allah! I know that thou art nothing more than a stone, powerless to do harm or be of any use, and if I had not seen the Prophet kiss thee, I should not have kissed thee!" In like fashion, by the "Sa'y" and the ablutions at the well of Zamzam, Mohammad kept alive the touching remembrance of the Arab's ancestor Ishmael and of his mother Hajar (Hagar). "Being too weak to carry any farther her wretched child succumbing athirst in a horrible desert, Hajar placed her offspring on the ground in the shade of a shrub and ascended a hill, hoping to see from afar a well or spring; but all in vain. Then, fearing that the soul of Ishmael might have escaped from his body, she came back, panting, to his side, and climbed another hill for the same purpose, but with no more success than before. So she went down again, tortured by the same anguish. "Seven times did she run in despair between the two hills until, maddened, she thought she would only find a corpse, when she caught sight of her beloved son quenching his thirst at a spring which, by order of the Compassionate, had gushed forth under the heel of the poor child. And to this miraculous well was given the name of Zamzam." In imitation of Hajar, pilgrims pass seven times along the path of agony which she trod between the two hills known as Safa and Marwa, and it is their duty to drink and perform their ablutions at the Zamzam spring.