In Madina there was a coosiderable number of Jews. They were wealthy and commanded influence. The Holy Prophet followed the policy of "live and let live". He accordingly entered into a treaty with the Jews. According to the terms of the treaty the Jews were to enjoy religious freedom and there was to be no interference in the religious affairs of the Jews by the Muslims. The Muslims and the Jews were to be on friendly terms and were to help each other in the promotion of objects of mutual interest. It was stipulated that the Muslims and the Jews would help each other in case of an attack by an enemy. No party was to give protection to the Quraish, and in case the Quraish invaded Madina both the Muslims and the Jews were to join in the defence of the city.

The Jews knew that in their holy books there were references to the advent of a prophet in Arabia. They were under the impression that the prophet would rise from their midst. When the Holy Prophet appeared from the ranks of the Quraish in Mecca, the Jews recognised in him all the signs of prophethood foretold in their sacred books. When the Holy Prophet came to Madina the Jews thought that he would be subservient to them. When the Holy Prophet followed an independent policy, the Jews embarked on a campaign of ridiculing Islam, and resorted to activities hostile to the Muslims.

Umar knew Hebrew, and he could talk with the Jews in their own language. Umar was a trader, and he had business contacts with the Jews. Out of the Muslims, Umar was popular with the Jews. One day the Jews gave him a copy of the Torah. Umar brought the copy to the Holy Prophet and said, "Messenger of God, this is a copy of the torah." Other companions including Abu Bakr were sitting with the Holy Prophet. The Holy Prophet paid no attention to what Umar had said. When Umar received no reply he began to read some passages from the Torah to the obvious displeasure of the Holy Prophet. Turning to Umar, Abu Bakr said, "Confound you, do you not see how God's Messenger is looking?" Umar looked at the Holy Prophet and said "I seek refuge in God from the anger of God and His Messenger. We are satisfied with God as Lord, with Islam as religion, and with Muhammad as prophet". Then the Holy Prophet said, "By Him in Whose hands Muhammad's life is, were Moses to appear to you, and you were to follow him and abandon me, you would err from the right path. Were he alive and come in touch with my prophetic mission, he would follow me." And then referring to the Jews the Holy Prophet said, "The Jews betrayed their own prophet; how can they be your friend?"

Umar asked some of his Jew friends whether there were any references to the Prophet Muhammad (peace be on him) in their scriptures. They answered the question in the affirmative. "Then why don't you accept him" asked Umar, and they said,"God sends him messages through Gabriel and Gabriel is our enemy." Umar told of this talk to the Holy Prophet. A few days later, God revealed to the Holy Prophet:

"O Apostle tell them,

Whosoever is the enemy of Gabriel,

Let him be so at his peril.

Verily God is the enemy of infidels." 2: 97-98

After this revelation, Umar broke up all contacts with the Jews.

When one of the Jewish tribes in Madina, Bani Qainuqa violated the terms of the treaty with the Muslhns, the Holy Prophet consulted his companions as to the action to be taken against the Jews. Some of the companions were in favour of conciliation, but Umar counselled that they should be expelled from Madina. They were accordingly expelled from Madina.

The Jews of the Banu Nadir clan affected to be submissive, and they were allowed to remain in Madina. Some time in A.D., 626 the Holy Prophet along with Abu Bakr and Umar went to the Banu Nadir Jews to claim blood money for a man murdered by a Jew. The Jews affected great humility, spoke words of flattery, and assured the Holy Prophet that they would comply with any order that he issued. As such they assured that the blood money demanded would be paid. Secretly the Jews deputed a man to climb on the roof of the house where they were sitting and from there hurl a stone on the head of the Holy prophet, as if it was an accident. It was revealed to the Holy Prophet that the Jews meant mischief.

The Holy Prophet accordingly rose from the place where he was sitting and returned home. His companions followed suit. The next day the Holy Prophet deputed Umar to tell the Jews that they should evacuate Madina. They hesitated. There followed a skirmish in which the Jews were overpowered. They were accordingly deported from Madina. Some of them went to Khyber and some went to Syria.