After their expulsion from Madina most of the Jews settled at Khyber. They were a cunning and crafty people, and were notorious for their intrigues. The Hudaibiyah pact provided for peace between the Muslims and the Quraish for a period of ten years. This meant that the Quraish could no longer openly aid the Jews against the Muslims. In spite of this change in the situation, there was no diminution in the hostility of the Jews against the Muslims, and they conspired to form another coalition against the Muslims.
To forestall the evil designs of the Jews, the Holy Prophet marched to Khyber in 629 C.E. with a force of 1,400 Muslims. The Jews shut themselves in their forts. These forts were formed of frowning walls built of the living rock and were considered invulnerable. The Jews thought that in these forts they would be able to defy the Muslims. The Jews had ample provisions, and there was no shortage of arms with them. The battle waged for some days with no tangible result. The Muslims attack became more violent, and they succeeded in capturing one of the Jewish forts named 'Naam'. Uthman was the first to climb the walls of this fort. The second person to climb the walls was Mahmud b Salma. The Jews stoned from above. Mahmud b Salma was martyred, but Uthman remained unhurt. He was the hero of the day and the Holy Prophet appreciated his feat of bravery. The Jews surrendered, and peace was concluded on the Jews agreeing to pay a tribute equivalent to one half of the land produce.
The battle of Khyber had far reaching consequences. It established the paramountcy of the Muslims in the Arabian peninsula. The Jews now became the subject of the Muslims. The Quraish thus lost the support of the Jews, and as such the battle of Khyber paved the way for the conquest of Makkah.
At Khyber, a Jewish lady served poisoned meat to the Muslims. Bishr b Bra one of the companions who ate a good deal of the meat died on the spot. Uthman did not taste the meat and thus escaped from the effects of the poison.