When the Muslims established themselves in Madina, and succeeded in acquiring strength, the Quraish of Makkah fumed and fretted at the success of the Muslims. Fearing lest Islam might be accepted by the tribes in the immediate neighborhood Of Madina, the Quraish heavily bribed these tribes not to be moved by any overtures by the Muslims. Some of the missionaries sent by the Holy Prophet to these tribes were murdered. The Jews of Madina had expected that the Prophet they were looking for would be a prophet of the Jews and would promote the Jewish faith, but when the Holy Prophet began to preach Islam which was an improvement on the Jewish faith, they became hostile to the Muslims. The Quraish of Makkah incited the Jews of Madina to create difficulties for the Muslims in Madina. In Makkah the Muslims were traders. In Madina the people who accepted Islam, and came to be known as "Ansar" were agriculturists. All trade in Madina was in the hands of the Jews. When the Muslim emigrants tried to undertake trading activities in Madina, they had to face competition and hostility of the Jews. The Holy Prophet realized that in the circumstances the Muslims would have to wage a war against the Quraish and the Jews on the economic front. The caravan route from Makkah to Syria ran close to Madina. There were some danger points on the route where the caravans could be ambushed by a small force. The Holy Prophet decided that in order to break up the trade monopoly of the Quraish, their caravans should be ambushed by the Muslims at strategic points.