The date is still the first year of Umar's caliphate.
Arabia, a place that had known no ruler, has become unified by Islam; the hearts and minds are open to the reality of Islam. Arabia now turns to the world geography to present the blessings of the revelation to humanity. The only door that opens to the world from Arabia is to the north, and it is defended by the two superpowers of the period. Thus, those whom the soldiers of Islam, who have been baked hard in the hot desert, must address are the Byzantines in Syria and the Sasanids in Iraq.
In order to understand, to some extent, what kind of spiritual state could oppose these two world giants at the same time let us advance to the interior of Iraq. On the shores of the Euphrates, near the most important city of the Sasanids, Qadisiya, the Muslims of the Islamic army were busy making the final preparations for an action that would open the doors to Northern Iraq and Iran. In the struggle that had continued for some time on the Iranian front the believers were commanded by the senior soldier in the Battle of Badr, Sa'd b. Abu Vakkas.
The sword was out of its sheath; however the followers of this religion, the message of which was peace, with every step were trying a new diplomatic attack to carry out a conquest without battle. The ambassadors who had been sent one after the other to the young ruler of the Sasanid Empire, Yezdigerd, called him to accept Islam or to pay jizye (tax levied on non-muslims). However, the attitude of Yezdigerd, who was trying to prove himself, was clear; he was abrupt and scornful.
The Iranian army, which was waiting that day by the Euphrates, waiting to overflow like a human flood, was engulfed in a tense and deep silence. There was only one noise other than the roar of the Euphrates, fed by the melting snow from Anatolia: the sound of the hooves of the meager horses that the Arab ambassador had mounted. Riding through the magnificence that was arranged to intimidate, approaching with dignity and assured steps between the distinguished members of the Iranian army in their dazzling armor, the Arab ambassador advanced.
The ambassador, without reining in his horse, comes into the tent where Rustem, a commander of the Iranian army whose fame had reached Medina is sitting; one side of the tent is open and it is covered with rugs which silence the sound of the horseshoes. The guards prevent this man from advancing, a man who does not have palace etiquette. The ambassador, dismounting, walks onto the carpets with a dignified stride, echoing the horseshoes. On one side of Rustem is the assistant with colorful armor, on the other a Meci priest, wrapped in white from the cap on his head to the cover over his face; Rustem is sitting comfortably on his mother-of-pearl inlaid throne; the ambassador approaches the throne but the guards stop him again. The ambassador's sword is tied to his waist with the jugular vein of a camel and it is wrapped in old cloth; under the tense gaze of the guards he returns to his horse and calls to Rustem from there. Giving a dignified greeting, he introduces himself "I am Mugire b. Shu'ba".
Rustem has difficulty understanding how a society that emerged from the desert could challenge such a victorious state and a magnificent army. He intends to destroy Mugire with the power he has taken from the army that dwells along the length of the Euphrates. Rustem feels great rancor that despite the rags Mugire is wearing he still bears a self-confident look on his face.
Rustem presents a generous bribe to Mugire; they believe that the Arab representative has left his land because he cannot make ends meet or due to violence: "Clothing, a mount and a thousand dirham at your disposal, and a load of dates to each one of you if you go and return to your land."
The answer that Mugire gives, which will cause the screams of war to resound in the Euphrates, is a slap in the face, not just for Rustem, but for all the minds that have difficulty understanding the basic philosophy on which the Islamic conquests are based:
"We have not come in pursuit of worldly goods. We are here to turn you from worshiping the manmade to worshiping Allah. Our men love dying for this cause as much as your men love their lives. I am calling you to Islam; if you accept you will be one of us. If you do not, I surrender to you the peace of Islam and offer you the opportunity to pay jizye. If you do not accept this, then it is war."
These words send a cold wind that extinguishes the holy fire that is burning in the corner of the tent; the arrow has started its flight. The believers devote themselves to fighting a superior force that is supported by elephants for three days. Finally upon the death of the proud Rustem the doors to Iraq and Iran are opened to the Muslims.
Qadisiya represents the essence of the concept of Islamic conquest. This essence, which commemorates the word "conquest" as the opening the hearts and minds to the truth of Islam via military campaigns, aims at bringing to all human hearts and minds, from the slave to the ruler, that which Prophet Muhammad preached to all humanity.
The reflections of the conquest philosophy can be seen in how the representative of the Alexandria head bishop and the emperor Cyrus described the believers when he saw them going to conquer Babylon at the time of Umar. "They were such people that down to the last one they preferred death over life, humility over fame and not one of them was the least bit interested in this world. It was as if their leaders were one of them; one could not separate the high ranking from the ordinary, the owner from the slave. When it was time to pray not one of them remained behind; all of them washed their faces and hands with enthusiasm and ran to pray."
The success of these military troops, without any organized battle experience, against armies that had centuries of experience and much training and order, was fed by experiences that had been guided by Prophet Muhammad (pbuh) at the battles of Badr, Uhud and the Trench; without these, the philosophy of the Islamic conquest cannot be understood. The largest, fastest and most effective, and more importantly the most permanent, conquests in human history, without a doubt were the result of this concept which focuses on the conquest rather than the victory.