With the defeat of the enemies of Islam at Badr and Uhad the enemies were by no means idle. Far and wide the idolators and their allies had sent their emissaries to stir up emotions against the Muslims. The Jews were the most active in this effort.
Huyay bin Akhtab, the leader of the banished Banu Nadhir tribes, began to enlist the support of all other Jewish tribes, the Arab tribes and the Quraish of Makkah in order to make a concerted effort to wipe out the Muslims for ever. The strategy of these combined forces also included the Banu Quraizah who were still living in the vicinity of Madinah. They were expected to attack the Muslims from within the boundaries of Madinah. They were considered by the Muslims as the most vicious and treacherous of all the Jewish tribes.
Rasulullah was aware of the evil planning of the enemies of Islam. He held an urgent mushwarah (consultation) with the Sahaaba and plans were made for the defence of Madinah. All the women and children were to remain in the city while all the men were together on Mount Sal'a outside Madinah. A learned Persian Sahaaba, Hazrat Salman Farsi (R.A.) explained to Rasulullah a system of effective protection. It was by means of a ditch, and Hazrat Salman Farsi (R.A.) had seen it practiced in his own country. Rasulullah was impressed by the idea and this ditch was ordered to be dug immediately. All the Muslims, trusting in Rasulullah 's farsightedness, set upon ardently to work.
The Muslims dug a deep trench five meters deep and five meters wide on the sides round the unprotected quarters of Madinah from which the enemy attack was imminent. On two sides there was the protection of the high lava rocks while on the third side were the thick palm groves of Madinah.
The tremendous task of digging the trench was zealously tackled by the Ansaar and the Muhajireen. There keenness was further increased by the fact that Rasulullah personally joined them in the digging. The shovel fulls of earth accumulated, thrown up with great spirit by the workers; and the ditch had reached a good depth, when suddenly the pick-axes struck against a rock which they were powerless to uproot. This was brought to notice of Rasulullah Rasulullah came there and struck the rock with the blows of his axe, the rock splitting into countless fragments under the blows of the axe. On every blow a spark appeared which the Sahaaba also witnessed. On every spark Rasulullah saw Syria, Iran and Yemen respectively. Rasulullah gave the glad tidings that these lands will eventually come under the banner of Islam.
Scarcely was the ditch ready, when the entire plain was covered by the tents of the enemy's army, ten thousand strong; the Quraish, Banu Kinanah, Ghatafans, Arabs of the Tuhamah and of the Najd with 4000 camels and 300 horses under their supreme commander Abu Soofyan. The enemy were dismayed at the defence prepared by the Muslims as they had never seen such a trench before.
The trench prevented any form of direct fighting. Both sides had to contend with shooting arrows at each other. When Amr ibn Wudda, an Arab, managed to cross the trench, he was killed immediately by Hazrat Ali (R.A.) with his famous sword 'Zulfiqaar'. Ikramah bin Abi Jahl and Hubayrah bin Wahab also tried to cross the trench but were repulsed. Naufal ibn Abdullah with the intention to assassinate Rasulullah tried to cross the trench but fell into it, he broke his neck. In order to retrieve the body the Mushriqeen (Kuffaar) offered Rasulullah the sum of 10,000 dirhams. Rasulullah said:
'He is wicked and any price in lieu of him is also wicked'.
Rasulullah handed over the body without accepting the offer.
With the prolonging of the siege the Muslims were becoming impatient. Icy north winds, which blows very often in winter in Madinah, benumbed their shivering bodies, provisions were lacking; the pangs of hunger would have paralysed their strength if it had not keen kept up and rekindled by Imaan, for all they had to eat were few grains of barley and dates. Moreover, there was always the fear of an attack by the Banu Quraizah on the women and children in the city.
Huyay bin Akhtab, an enemy of Allah, approached Ka'ab ibn Asad, prince of the Banu Quraizah, who although deeply hostile to Rasulullah had signed a 'Treaty' with the Muslims. Huyay influenced Ka'ab ibn Asad into dishonouring his treaty with Rasulullah and formed an alliance with the infidels. However the Banu Quraizah wanted an assurance from their infidel allies that they will be protected by them in the future, whatever the outcome of the war.
The news of this defection came to the notice of Rasulullah . He immediately sent Hazrat Sa'ad ibn Mu'az (R.A.) , Hazrat Sa'ad ibn Ubaida (R.A.), Hazrat Abdullah ibn Rawaahah (R.A.), and Khawwaat ibn Jubair (R.A.) to find out if this was true.
When the envoys reminded the Banu Quraizah of their 'Treaty' the following replay was given:
'Who is this Prophet of Allah of whom you speak? There exist no treaty between him and us'.
This was downright treachery, for the Banu Quraizah were very well informed as to the secrets of the Muslims and the weak points of the town. This treacherous news immediately prompted Rasulullah to make special arrangements for the security of the women, children and the old people who were left behind in the city. He appointed two groups of soldiers, consisting of 200 and 300 men under the command of Hazrat Asalamah ibn Aslam (R.A.) and Hazrat Zaid ibn Harith (R.A.) respectively, to take turns to look after those who were left behind in the city. They used to recite 'Takbeer' loudly to frighten the enemy so that they might think that the Muslims had kept a large force for the protection of there women and children and therefore refrained from attacking.
Rasulullah considered it necessary first to dispel the fears of the men at the battlefield about the safety of their families left behind in the city, secondly to provide a sufficient defensive force in case the Jews of the Banu Quraizah attacked. These measures assured the security of the town and the men could now face the enemy with full satisfaction and confidence.
The kuffaar army kept up a sporadic attack, raining showers of arrows across the trench while the Muslims were hard pressed with defending any weak opening in their defence. Both the Muslims and the kuffaar were frustrated with a war that showed no signs of reaching a settlement. A sad incident for the Muslims was the serious wound received by Hazrat Sa'ad bin Ma'az (R.A.) when a stray arrow from the enemy was embedded in his shoulder.
Judging the critical situation Rasulullah resorted to military tactics. Rasulullah sent Na'im ibn Mas'ud (R.A.) a member of the Ashja tribe of Bani Ghatafaan whose conversion to Islam was not yet publicly known. He went first to the Quraizite Jews and said:
'You are not sure at this stage that the Makkans will succeed in this war. Once the foreign invaders return as they must do sooner or later, you can not defend yourselves singke-handed against Muhammed . So do not involve yourselves without first getting a guarantee that the Makkans will fight their former co-citizens to the end. Ask them for hostages as an assurance to side with them (Quraish)'.
The Quraizaites found this advice reasonable. Then Na'im ibn Mas'ud went to the Quraishite camp and told them according to his information, the Quraizite Jews had entered into conspiracy with Muhammed and as an assurance of their friendship, had promised to get hold off some of the Quraishite prominent personalities and hand them over to him (Muhammed ).:
'Beware of these Jews. Rather ask them, as their assurance of their co-operation with you in the common struggle; for the Muslims would be off their guard on that day in respect of the Jews'.
After giving similar advice to the Ghataffanites and other enemy group. he returned to the Muslim camp and spread the rumour that the Jews were asking the invaders for hostage in order to hand them over to Muhammed . Rasulullah was informed of the rumour in the Muslim camp, on hearing this remarked:
'Maybe we ourselves should order them (Jews) to do that'.
Mas'ud al-Nammam, an ignorant old man hurried to the Quraishite camp, and just for the sake of looking well informed, told the Quraishite commander Abu Soofyaan, what the Prophet of Allah had remarked about his having asked the Jews to demand hostages.
Abu Soofyaan and the Chiefs of the Ghataffans sent Ikramah ibn Abu Jahl to the Banu Quraizah delegating him to say to them:
'We can no longer stay in these parts so unsuitable to our horses and camels. Be ready to fight Muhammed tomorrow. We must get rid of him'.
The Banu Quraizah answered:
'Tomorrow is Saturday, the Sabbath day, which means obligatory rest in our religion. But at any rate, we cannot fight by your side unless you grant us hostages chosen from the most noble among you, as a guarantee that you will not abandon us before having crushed our common enemy'.
When Ikramah ibn Abu Jahl repeated these words, the Quraish and the Ghataffans cried out:
'By all our Gods, what Na'im told us concerning the Banu Quraizah was perfect truth'.
They immediately sent another message declaring plainly:
'By our gods, we will not give you a single hostage'.
The sacred month of Shawwal was nearing the end; Zil-Qadah, was approaching, in which the Quraish had reasons to be back in Makkah to receive pilgrims rather than fight and thus violate their superstitions regarding the months of the truce God. They found food stocks had been exhausted, the season also had worsened, and a chill and terrific hurricane uprooted every tent in the enemy camp. Abu Soofyaan decided to return home to Makkah and others followed. It is said that Abu Soofyaan was so terrified that he jumped on the back of his camel, which was sitting and wanted to raise it, not remembering that its legs were tide with rope. Even so the shrewd Makkan chief did not forget in his haste to command Khalid bin Walid and Amr ibn al-As at the head of 200 horsemen, to be ready for support action in case of Muslim pursuit. Thus the great enterprise of the Jewish-Makkan conspiracy came to a fruitless end, lasting for twenty seven days.
With the return of the Muslims into Madinah and the jubilant cries of 'Allahu Akbar' (Allah is Great), ringing into their unholy ears, the Banu Quraizah cowered (rebounded) in their fear and guilt at the thought of what the Muslims would do to them for their conspiracy with the kuffaar. They began to hole up in their fortress with food and other necessities.
A Divine revelation brought by Hazrat Jibra'eel (A.S.) commanded Rasulullah to give out punishment to the Banu Quraizah. The Muslims laid a siege to their fortresses, and after 25 days, the Jews gave in and tried to appease the Muslims. They proposed to Rasulullah that Hazrat Sa'ad bin Mu'az (R.A.) who was their friend prior to accepting Islam be asked to decide their issue. In this way they were to get a favourable settlement for themselves. Rasulullah agreed to their request.
Hazrat Sa'ad bin Mu'az (R.A.), who was seriously wounded, was brought with difficulty to the sector of the Banu Quraizah. Hazrat Sa'ad bin Mu'az (R.A.) gave his decision thus;
The verdict was justified in three aspects of its execution. Firstly, the Law of Taurah had been applied. Secondly, when Madinah was attacked from all sides, the Banu Qraiziah were bent on mutiny from within Madinah. Thirdly, they did not trust the Nabi of Allah, but gave preference to Hazrat Mu'az (R.A.) because of his previous friendship with the Jews. Hazrat Mu'az (R.A.) proved his loyalty to Islam and his verdict reflected the justice of Islam and the love for Allah and his Rasul .