The Battle of the Trench took place after the campaign against Banu Nadir, who had been expelled from Madina for their treachery and who had mostly joined their Jewish brethren in Khaybar.

In the fifth year of Hijra, a group of those Jews including Sallam ibn Abi al-Huqayq and Huyayy ibn Akhtab, together with a number of Banu Wa’il, left for Makka. They urged the Quraysh to make war on the Prophet Muhammad, upon him be peace and blessings, and promised help and support.

The Jewish group then went to the tribes of Ghatafan and Qays Aylan and guaranteeing them help also, encouraged them to fight against God’s Messenger. (1)

These intrigues of the Jews resulted in the formation of a great confederacy against Islam. It consisted of the Makkan polytheists, the desert tribes of central Arabia, the Jews previously expelled for treacheries from Madina, the Jews (Banu Qurayza) remaining in Madina, and the hypocrites led by Abd Allah ibn Ubayy ibn Salul. The last two constituted a treacherous network within Madina.

When God’s Messenger, upon him be peace and blessings, heard, through his intelligence service, of the gathering of the allies or confederates (ahzab) against him, and the strength of their desire to fight against him, he consulted his Companions, as he always used to do. It was their unanimous view that they should remain in Madina and fight from there. Salman al-Farisi suggested to God’s Messenger that they should dig a trench around Madina.

The trench took six days of feverish work to dig. God’s Messenger had divided them into groups of ten people and put them to a competition. It was a hard task and time was restricted; what was more, hunger struck them all; yet all the Companions worked enthusiastically. In order not to feel hunger, each fastened a rock around his belly. While digging they recited:

We are those people who
Took the oath of allegiance to Muhammad;
Therefore we shall fight in the way of God
As long as we live.
By God, if God had not enabled us to,
We would have neither been guided
Nor given alms, nor performed prayers.
Send down unto us calmness and tranquillity
And make our feet firm if we confront the enemy! (2)

The Messenger, who dug alongside them, and had fastened around his belly two rocks, answered them with the couplet:

O God, the real life is the life of the Hereafter
So, forgive the Helpers and the Emigrants. (3)

The allies advanced against Madina in the hope of destroying the Muslims in a battle to be fought in an open field. However, when they faced a new strategy of God’s Messenger, they took the first blow. Numbering around 20,000 men, they camped near the ditch. The Madinan fighting strength was no more than 3,000, and the Jewish tribe of Banu Qurayza and the Hypocrites were a source of weakness as they were treacherously intriguing with the enemy. As stated in the verses of the Qur’an (al-Ahzab, 33.12–20) when the Hypocrites first saw the enemy, they were already in a defeatist mood. Not content with disloyalty themselves, they tried to infect others, who made paltry excuses to withdraw from the fight. If the enemy were to gain entrance, they were ready to betray the city to the enemy.

The sagacity and military genius of God’s most noble Messenger, upon him be peace and blessings, showed themselves once more during the Battle of the Trench. He had kept them confined within the city and stationed them in a way that they could safeguard their homes against possible attacks from Banu Qurayza. It was the most critical moments of the war when Banu Qurayza sent a man into the city to spy into the conditions of the Muslim women. However, when this man was killed by Safiyya, the Prophet’s aunt, their hopes were frustrated. (4)