The Jews of Madina after their banishment were now settled in Khaiber, a stronghold of the Jews of Arabia. But they had neither forgiven nor forgotten the Prophet (S.A.W) for their ouster. Their anger and hatred of him was more because of their disappointment they got from him. When the Prophet (S.A.W) came to Madina they saw him and his followers offering their prayers facing Palestine. They thought that his preachings were another form of Judaism and the Prophet (S.A.W) was actually one of them and that they can make best use of him. But when they realized that his teachings had broken their monopolies in business and that his preachings were against capitalism their basic creed and the Prophet (S.A.W) asking the Muslims neither to pay interest or take interest which means their losing the control on the economy of Madina, they began fearing him, and when they saw that he has even changed the direction of their prayers from Palestine to Mecca they started hating him and wanted to kill him. And for this cause they had the support of even many rich Muslims of Madina who had lost their distinctions because of the teaching of equality and brotherhood by the Prophet (S.A.W). At the time of embracing Islam they had never thought that this religion will make them sit and pray with humble slaves and poor people. But were now helpless as the Muslims were now a bigger force which could not be easily dispensed with. So they began to conspire with the Jews to annihilate the Muslims completely.
Khaiber is a place some eighty miles from Madina and an old Jewish settlement. Here the Jews from Palestine and other places had settled after their banishments. And gradually this thickly populated settlement had developed into a big market. The place was also considered safe because it was surrounded by six strongly built forts. The strongest and the biggest being Kamoos. (Khaiber in Hebrew means fort). They thought that being in Khaiber they were very secured and they could do any harm to the Muslims from there for which they cannot be punished. They occasionally raided the outskirts of Madina, looting and plundering the fruit trees and carrying away their cattles.
One day when they killed the son of Abu Zar-e-Ghaffari who was looking after the cattle of the Prophet (S.A.W), the Prophet (S.A.W) sent Abdulla Bin Rawaha to warn them for doing such crimes.
But they refused to listen to Abdullah and Abdullah returned disappointed. The Prophet (S.A.W) also got the news that the Jewish tribes of Bani Ghaftan, Bani Asad and Bani Kanana had again regrouped under the command of Marhab, the famous Jew warrior of Khaibar. The Prophet (S.A.W) who was very much involved in dealing with the hypocrites of Madina did not want to fight on two fronts. But when he saw that the Jews of Khaibar would not allow him to live in peace and would attack any moment, he decided to counter attack them at Khaiber itself before they could attempt to over run Madina. Taking some fourteen hundred people the Prophet (S.A.W) marched towards Khaiber.
The Prophet (S.A.W) on reaching Khaiber got an attack of migraine, he had to confine himself to his tent, and due to severity of the pain could not do anything. Ali (A.S.) too was suffering from conjunctivitis and was lying in his tent. Umar ibn Khattab without consulting the Prophet (S.A.W) took the flag of Islam himself and went to attack the enemies but could not face the onslaught of the enemies and soon returned without any fight. Next day the Prophet (S.A.W) gave the flag to Abu Bakr but he too ran away without giving any fight disappointing the Prophet (S.A.W). Third day Umar again took courage and asked for the flag but soon came back from the battle field. When the Prophet (S.A.W) questioned him, he blamed the soldiers for not standing by him and called them cowards. And when the Prophet (S.A.W) questioned the soldiers about their flight from the battlefield they blamed Umar and called him impotent.
The Prophet (S.A.W) was pained to see the state of affairs of the Muslims and their defeat for three consecutive days. Now the victory of the Muslims had become a necessity because the Prophet (S.A.W) feared that the hypocrites of Madina may also raise their heads on hearing the news of these defeats. Addressing the Muslims that evening the Prophet (S.A.W) said, "Tomorrow I shall give the banner to a person, who is brave, who will attack and not run away from the battlefield. He is the lover of Allah and His Prophet (S.A.W) and Allah and His Prophet (S.A.W) also love him. This person will not return from the battlefield without achieving victory." [Bukhari, Vol. 3, Page 33] This prediction of the Prophet (S.A.W) became the cause of sleepless nights for many. Victory was now certain and guaranteed, who ever carries the flag will not die, and return victorious. So why not have it. Next morning, when the Prophet (S.A.W) rose to speak to the Muslims, many of them who had desired to be "that lucky person" sat erect so that the Prophet (S.A.W) may not overlook him. Umar speaking of his own feelings on that night said, "That was the day when I desired to be that man the Prophet (S.A.W) had predicted, and it was on that day that I dreamt of becoming the Amir (ruler)." [Izalatul Khefah, Vol. 2, Page 49] When Ali (A.S.) was told about the Prophet (S.A.W)s prediction he said, "O Allah if you do not want to oblige anyone, no one can, and when you want to oblige anyone, who can stop You."
Next morning the Prophet (S.A.W) summoned Ali (A.S.) from his sick bed, and after curing his conjunctivitis by applying his saliva, gave him the flag of Islam and ordered him to proceed to the battlefront. Ali (A.S.) asked, "Have I to fight till they embrace Islam?" The Prophet (S.A.W) replied, "No teach them Islam and show them their duties towards Allah. If they dont agree ask them to have peace. By Allah if you succeed in converting even one Jew to Islam, it will be more than finding a red camel, which I am sure you will sacrifice it in the name of Allah."
Ali (A.S.) wearing a red gown, went near the fort of the Jews and posted his flag on a stone. A Jew priest watching Ali (A.S.) from the fort asked, "O Flag bearer who are you and what is your name." When Ali (A.S.) gave his name he declared to his people, "Beware I swear on Torat that you will be conquered." [Mir Dariyun Naboowa, Vol. 2, Page 30] Haris Judah brother of Marhab rushed out of the fort and killed some Muslims. Ali (A.S.) challenged him and finished him then and there. Seeing his brother dead Marhab himself came out of the fort with his crack force and began to speak of his valour, strength and courage. "I am the one whose mother has named him Marhab." In reply Ali (A.S.) said, "I am the person whose mother has given him the name of Asad (Lion) and I am as dangerous as the Lion of the forest." Marhab taking the initiative attacked Ali (A.S.), but Ali (A.S.) avoided the blow and tendered such a fierceful blow on his head that it cut his helmet, turban and rested on his teeth. Marhab fell dead and his companions fled back to the fort. Ali (A.S.) followed them and took the fort by storm, broke the gate single handed and carried his army inside the fort, and within hours the flag of Islam was flying on the biggest fort of Arabia.
Seeing Ali (A.S.) returning victorious the Prophet (S.A.W) rushed out of his tent, to receive him. He embraced him and kissed his forehead, and said, "Ali I have received the news of your great achievement, O Ali which is worthy of my thanks and this is the obligation O Ali no Muslims can forget. Allah has appreciated your services and I am very much pleased with you." Hearing these words of compliment from the Prophet (S.A.W) of Islam Ali (A.S.) began to cry. The Prophet (S.A.W) asked him if these tears were of joy or sorrow? Ali (A.S.) replied that these were the tears of joy. "Why should I not be happy when you are pleased with me." The Prophet (S.A.W) remarked, "Not only that I am pleased with you, even Allah is pleased with you. O Ali (A.S.) I am afraid I cannot speak much about you because I am afraid the Muslims on hearing my views may give you the status the Christians have given to Jesus. But know this that you are to me as Haroon was to Moosa. You will fight for my cause and you will be the nearest to me on the Day of Judgement. You will be next to me on the fountain of Kausar. Enmity against you is enmity against me. A war against you is a war against me. You flesh is my flesh, your blood is my blood. Who obeys you obeys me. Truth is on your tongue, in your heart and in your mind." [Tareekhe Khamees V.4 pg. 53].
Speaking about Ali (A.S.)s virtues Umar moaned and said out of three distinctions and favours which Ali (A.S.) received if he had received even one of it would have been like finding a red camel. And naming he said:-
(1) The order of the Prophet (S.A.W) to his companions to close the doors of their houses which opened in the mosque except Ali (A.S.)s doors,
(2) Marrying his daughter Fatema (S.A.) to Ali (A.S.) and
(3) getting the flag at Khaiber.
When the people of Fadak saw the fall of Khaiber which they had considered to be their source of strength and protection they settled with the Prophet (S.A.W) and signed a peace treaty with him, giving the Prophet (S.A.W) half of his cost. The Prophet (S.A.W) agreeing to their suggestion allowed them to cultivate it on his behalf. For these gardens and land the Prophet (S.A.W) had an income of seventy thousand Dinars.
When the revelation from Allah came, "And give to the near of the kins his (or her) dues and to the needy and wayfarer and spend your earnings wastefully." (17-26 Holy Quran). The Prophet (S.A.W) gave Fadak to Fatema (S.A.) and her children in place of all the wealth her mother Khadija had spent for the cause of Islam. Fatema (S.A.) after receiving those fields from her father brought changes in the management of those farms.