The Jewish Fast of Atonement, which plays so important a part in Semite faith and doctrine, had been made part of the Muslim ritual in 622, while a federal union still seemed possible, but the next year such an amalgamation could not take place. In Ramadan (Dec. to January), therefore, Mahomet instituted a separate fast for the Faithful. It was to extend throughout the Sacred Month in which the Kuran had first been sent down to men. Its sanctity became henceforth a potent reminder for the Muslim of his special duties towards Allah, of the reverence meet to be accorded to the Divine Upholder of Islam. During all the days of Ramadan, no food or drink might pass a Muslim lip, nor might he touch a woman, but the moment the sun's rim dipped below the horizon he was absolved from the fast until dawn. No institution in Islam is so peculiarly sacred as Ramadan, and none so scrupulously observed, even when, by the revolution of the lunar year, the fast falls during the bitter heat of summer. It is a characteristic ordinance, and one which emphasises the vivid Muslim apprehension of the part played by abstention in their religious code. At the end of the fast--that is, upon the sight of the next new moon--Mahomet proclaimed a festival, Eed-al-Fitr, which was to take the place of the great Jewish ceremony of rejoicing. At this time, too, Mahomet, evidently bent on consolidating his religious observances and regulating their conduct, decreed a fresh institution, with parallels in no religion--the Adzan, or call to prayer. Mahomet wished to summon the Believers to the Mosque, and there was no way except to ring a bell such as the Christians use, which rite was displeasing to the Faithful. Indeed, Mahomet is reported later to have said, "The bell is the devil's musical instrument." But Abdallah, a man of profound faith and love for Islam, received thereafter a vision wherein a "spirit, in the guise of man, clad in green garments," appeared to him and summoned him to call the Believers to prayer from the Mosque at every time set apart for devotion. "Call ye four times 'God is great,' and then, 'I bear witness that there is no God but God, and Mahomet is His Prophet. Come unto prayer, come unto salvation. God is great; there is no God but Him.'" "A true vision," declared Mahomet. "Go and teach it to Bilal, that he may call to prayer, for he has a better voice than thou." When Bilal, a slave, received the command, he went up to the Mosque, and climbing its highest minaret, he cried aloud his summons, adding at each dawn: "Prayer is better than sleep, prayer is better than sleep." And when Omar heard the call, he went to Mahomet and declared that he had the previous night received the same vision. And Mahomet answered him, "Praise be to Allah!"