After suppression of the revolt in Seestan, Ali once more turned to the affairs of Syria. By this time, a year had elapsed since the election of Ali. During this period, Muawiyah had added to his strength. He had persisted in his propaganda in the name of vengeance for the blood of Othman. Ali felt that the expedition against Syria had already been sufficiently delayed, and such immediate action to tackle the problem effectively was called for.
Although Ali had every justification to lead a military expedition to Syria forthwith, he nevertheless decided to explore the possibilities of arriving at a settlement through peaceful means in the first instance. He wanted to send an envoy to Muawiyah, and in this connection he looked for man who commanded some influence with Muawiyah. The choice of Ali in this connection fell on Jarir b Abdullah. He was the Governor of Hamdan under Othman. Ali had retained him in his office, and he had taken the oath of allegiance to Ali. He was a personal friend of Muawiyah. Ali summoned Jarir b Abdullah to Kufa, and commissioned him to proceed as his envoy to Syria and prevail upon Muawiyah to submit to the authority of Ali. Malik Ashtar the leader of the regicides advised Ali that Jarir should not be sent to Syria for he was a friend of Muawiyah, and he would promote the interests of Muawiyah, rather than those of Ali. Ashtar opted to go himself. As Malik Ashtar was involved in the assassination of Othman, Ali did not consider it advisable to send him as an envoy to Syria.
Jarir b Abdullah went to Syria. He was warmly received by Muawiyah. Jarir tried to persuade Muawiyah to submit to the authority of Ali. Ali, so argued Jarir was the elected Caliph, and in the interests of the solidarity of Islam it was necessary to maintain the unity of Ummah. Muawiyah detained Jarir, and asked him to see things for himself. In the main mosque of Damascus the blood stained shirt and the amputated fingers of Naila were displayed and as the faithful entered the mosque and looked at these relics they wept and mourned at the death of Othman. They took the oath that they would not rest content until they had avenged the murder of Othman. Jarir b Abdullah visited other cities in Syria, and everywhere he saw the people prepared for war to avenge the death of Othman.
Jarir b Abdullah returned to Kufa to report that the people of Syria were bent upon making war to avenge the death of Othman. On the failure of the mission of Jarir, Malik Ashtar said that he already knew that nothing could come out of his mission as he was Muawiyah's man. Malik Ashtar said that if he had been sent as an envoy the results would have been different. Jarir retorted that the people of Syria would have murdered him. Ashtar said that he would have first murdered Muawiyah. Hot words were exchanged between Malik Ashtar and Jarir. Jarir felt disgusted and shifted to Syria where he was well looked after by Muawiyah.