The Quraysh proceed towards the battle of al-Khandaq while Abu Sufyan was their leader.

In the month of Sha'ban of the fourth year of the Hijrah, the Prophet and his friends came to the land of Badr as they had agreed the year before. Abu Sufyan and the people of Mecca, too, left their city but after going some distance, they changed their minds and returned, but before doing so Abu Sufyan said to his supporters: "O men of Quraysh! This war would have been possible for you in the years of greenness and freshness of the desert. But nothing can be done. This year we are faced with a drought. So I will go back and you can follow my example."(46)
They obeyed him and returned to their city wondering when to start another war against Islam. Time passed and the fifth year of the Hijrah began. Then the Quraysh tribe headed by Abu Sufyan started their preparation of a war. Many groups gathered, and the confederation of the Quraysh including the Jews organized a large army under the command of Abu Sufyan in order to uproot Islam and Muslims.
The Muslims sat in consultation, and on the suggestion of Salman al-Farisi a wise man of Iranian nationality it was decided to dig a ditch round Medina.(47) The invaders reached Medina shortly after the defensive ditch was dug and the city was ready to face the enemy.
Abu Sufyan and his army besieged Medina for a month, but as the Arabs did not know how to overcome the barrier of the ditch in war, there occurred few clashes. Occasionally a warrior from the army of infidels found an opportunity to cross the ditch to attack the Muslim ranks. One of these was 'Amr ibn 'Abd Wud who had a fame as an Arab warrior. He leapt over the ditch with his horse and stood before the army of Islam and boastfully challenged them to fight.
No one dared to say a word and step forth for fear of death. Eventually no one but Imam 'Ali was prepared to take up the