When Noman bin Muqarrin received orders, he moved with his forces towards Nihawand and halted at Tazar. Here all forces from Kufa, Basra, and Madina also joined. All movements of the Muslim army were completed by December 641 when they were poised for an attack on the Persians.
After the troops had settled down at Tazar, Noman bin Muqarrin sent a reconnaisance party to locate the presence of the Persians. The party included Amr bin Maadi Karib and Taleaha. The party returned to report that they had found no Persians between Tazar and Nihawand.
Thereupon Noman ordered the march to Nihawand. After some days of marching the Muslim army arrived at Isbeezahan, eleven miles from Nihawand and here they halted.
The two armies now faced each other well poised for a life and death struggle Mardanshah the Persian General sent words to No'man to depute some emissary to the Persian camp for talks. No'man chose Mugheera bin Shu'ba for the purpose.
When Mugheera appeared before Mardanshah, the Persian General adopted a haughty tone and said:
"You Arabs are a people farthest of all from good, the most wretched, the most foul, and the most filthy. The only thing which prevents me from ordering my warriors to kill all of you is my aversion to the pollution which your corpses would cause, for you are unclean. If you go away, we will be rid of you and we may pay you something. And if you refuse to go, be prepared for your end."
In reply Mugheera after praising Allah said that his description of the Arabs applied to the Arabs before the advent of Islam. With the coming of the Holy Prophet and their conversion to Islam, things had changed. They were now the purest, and the cleanest. He added:
"By Allah, we have not ceased to receive victory and success from our Lord ever since His Prophet came to us. Now we have come to you carrying the message of Allah. You accept Islam, and that will be the end of hostility. If you do not accept Islam, but want to be at peace with us, then pay Jizya. If both these alternatives are not acceptable to you then only the sword will decide the matter between you and us."
That annoyed Mardanshah, and he said:
"If that is that, let the sword arbitrate".
Thereupon Mugheera returned to the Muslim camp. After hearing the account of Mugheera as to what had transpired at the Persian camp, No'man bin Muqarrin asked the Muslim troops to be ready for the fight.
A message was received from Mardanshah enquiring whether the Muslims would like to cross to the Persian side, or should they cross over to their side. Norman keen to take the initiative sent the word that the Muslims would cross over to the Persian side.