At this period the religion of Mahomet was spreading over the east, and in 637 the caliph Omar marched on Jerusalem, which capitulated after a siege of four months.
According to Moslem traditionists Mahomet declared that one of his descendants, the imam of God, who would fill the earth with equity and justice, would bear the name of al-mandi.
It is true that Arabian polytheism in the time of Mahomet was in a state of decay.
Ockley's book on the Saracens " first opened his eyes " to the striking career of Mahomet and his hordes; and with his characteristic ardour of literary research, after exhausting all that could be learned in English of the Arabs and Persians, the Tatars and Turks, he forthwith plunged into the French of D'Herbelot, and the Latin of Pocock's version of Abulfaragius, sometimes understanding them, but oftener only guessing their meaning.
The great rabbinic academies at Sura and Nehardea, the former of which retained something of its dominant role till the rrth century, had been founded, Sura by Abba Arika (c. 219), but Nehardea, the more ancient seat of the two, famous in the 3rd century for its association with Abba Arika's renowned contemporary Samuel, lost its Jewish importance in the age of Mahomet.