The moral effect of this disastrous battle was such as to encourage some neighboring nomad tribes to make forays upon the Medinite territories, but most of these were repelled.

The Jews also were not slow to involve in trouble the Prophet and his followers. They tried to create disaffection among his people and slandered him and his adherents. They mispronounced the words of the Qur'an so as to give them an offensive meaning. They also caused their poets, who were superior in culture and intelligence, to use their influence to sow sedition among the Muslims. One of their distinguished poets, called Ka'b, of the Bani An-Nadir, spared no efforts in publicly deploring the ill-success of the idolaters after their defeat at Badr.

By his satires against the Prophet and his disciples, and his elegies on the Meccans who had fallen at Badr, Ka'b succeeded in exciting the Quraish to that frenzy of vengeance which broke out at Uhud. He then returned to Medina, where he continued to attack the Prophet and the Muslims, men and women, in terms of the most obscene character. Though he belonged to the tribe of Bani AnNadir, which had entered into the compact with the Muslims and pledged itself both for the internal and external safety of the State, he openly directed his acts against the commonwealth of which he was a member.

Another Jew, Sallam by name, of the same tribe, behaved equally fiercely and bitterly against the Muslims. He lived with a party of his tribe at Khaibar, a village five days' journey northwest of Medina. He made every effort to excite the neighboring Arab tribes against the Muslims. The Muslim commonwealth with the object of securing safety among the community, passed a sentence of outlawry upon Ka'b and Sallam.