After the conquest of Sus, the only place of military importance in Khuzistan still left in the hands of the Persians was Junde Sabur. It lay to the north east of Sus.
Abu Musa wrote to Umar seeking orders whether Junde Sabur should also be captured. Umar approved the proposal for capturing Junde Sabur. He asked Abu Musa to send a column under Aswad bin Rabee'a to Junde Sabur. Aswad bin Rabee'a was a companion of the Holy Prophet and was nicknamed as 'Muqtarib' as he acted as a waiter on the Holy Prophet.
Aswad bin Rabee'a accordingly marched with a Muslim force from Sus to Junde Sabur. Like other Persian cities, Junde Sabur was also a walled city. When the Muslim forces reached Junde Sabur the Persian garrison shut themselves in the city.
The Muslims besieged the city, and set up military posts at all approaches to the city. The Persians made some attempts to sally forth and break through the Muslim lines but they failed. The Muslims also made some attempts to carry the city by assault but the attempts did not succeed.
One day the gates of the city were thrown open. The citizens came out unarmed, and attended to their normal functions as if the hostilities had ended. The Muslims were surprised at this, and enquired from the Persians as to how it was that they had ended hostilities.
The Persians said: "You offered us peace on the payment of Jizya and we have accepted the offer."
The Muslim Commander got in touch with the Persian Commander and said that he had not offered them any terms, and as such the war was not over.
The Persians thereupon brought an arrow along with a message that had been shot from the Muslim camp. The message had been shot with the arrow offering peace if the Persians were to surrender and pay the Jizya.
The Muslim Commander made an enquiry and it was revealed that from among the Muslim ranks a Muslim slave Mukannaf had on his own account shot the arrow offering peace to the Persians on the payment of Jizya.
That was followed by parleys between the Muslim and the Persian Commander. Aswad b Rabee a explained that the arrow with the message had been shot by a slave on his own account and carried no authority. The Persian view was that they had received the message from the Muslim side, and they accepted it. It was not for them to probe whether the message was backed with the necessary authority or not. The Persians said that they had accepted the message in good faith. If for any reason the Muslims wanted to go back on their pledge, it was open to them to do so, and in that case the hostilities could be resumed.
It was an embarrassing situation, and it was decided that the matter should be reported to Umar, and his instructions should be awaited. Till then it was decided to observe truce.
Aswad bin Rabee'a accordingly reported the matter to Umar. In reply Umar said:
"Allah be praised that He has given you the strength that the enemy surrenders even at the instance of a message that lacks authority. As the message was sent from the Muslim camp it has to be honoured even if it lacked due authority. Those who seek peace leave them in peace."
On receipt of these orders, peace was formally negotiated with the Persians, and their surrender was accepted on the payment of Jizya.