Rising Islam was as intolerant as Christianity. When Omar had driven the Jews out of Chaibar and the Christians out of Najaran, he gave instructions to his generals against the Jews and Christians. These orders were called "the covenant of Omar," and contained many restrictions against the "peoples of the Book" (Jews and Christians). They were not allowed to build new houses of worship, nor to restore those that were in ruins. They had to sing in subdued tones in the synagogues and churches, and were compelled to pray silently for the dead. They dared not hinder their followers from accepting Islam, and were compelled to show marks of respect to Mussulmans whenever they met them. Further, they were not allowed to fill judicial or administrative offices. They were forbidden to ride on horses, and had to wear marks whereby they could easily be distinguished from the Moslems. Jews and Christians were not allowed to make use of a signet-ring, which was considered a mark of honor. Whilst the Mahometans were exempt from taxes, and at most only had to pay a slight contribution for the poor, Jews and Christians had to pay a poll-tax and ground-rent. In spite of this fact, the Jews felt themselves freer under the new rule of Islam than they did in the Christian lands. The restrictive laws of Omar were not carried out even during Omar's lifetime, and though the fanatic Mussulmans scorned the Jews for their religion, they did not despise them as citizens, but showed great honor to worthy Jews. The first Mahometans treated the Jews as their equals; they respected them as friends and allies, and took an interest in them even as enemies. The Asiatic and Egyptian Jews consequently treated the Mahometans as their liberators from the yoke of the Christians. A mystical apocalypse makes a distinct reference to the joy experienced at the victory of Islam. Simeon bar Yochaï, who was looked upon as a mystic, foretells the rise of Islam, and bewails the same in the prayer which runs as follows: "Have we not suffered enough through the dominion of the wicked Edom (the Roman-Christian dominion), that the dominion of Ishmael should now rise over us?" Metatoron, one of the chief angels, answers him: "Fear not, son of man! God sets up the kingdom of Ishmael only in order that it may free you from the dominion of the wicked Edom. He raises up a prophet for them, he will conquer countries for them, and there will be great hatred between them and the sons of Esau" (the Christians). Such were the sentiments of the Jews with regard to the conquests of the Mahometans.