Confederate army made several other attempts to cross the trench during the night but repeatedly failed. Although the confederates could have deployed their infantry over the whole length of the trench, they were unwilling to engage the Muslims at the close-quarter as the former regarded the latter as superior in hand-to-hand fighting. As the Muslim army was well dug-in behind the embankment made from the earth which had been taken from the ditch and prepared to bombard attackers with stones and arrows, any attack could cause great casualties. Banu Qurayza The Confederates attempted several simultaneous attacks, in particular by trying to persuade the Banu Qurayza to attack the Muslims from the south. From the Confederates, Huyayy ibn Akhtab, a Khaybarian, the leader of the exiled tribe Banu Nadir, returned to Medina seeking their support against the Muslims. So far the Banu Qurayza had tried their best to remain neutral, and were very hesitant about joining the Confederates since they had earlier made a pact with Muhammad. When Huyayy approached them, their leader refused to allow him entry. Huyayy eventually managed to enter and persuade them that the Muslims would surely be overwhelmed. The sight of the vast Confederate armies, surging over the land with soldiers and horses as far as the eye could see, swung the Qurayza opinion in the favor of the Confederacy. News of the Qurayzah's supposed renunciation of the pact with Muhammad leaked out, and Umar promptly informed Muhammad. Such suspicions were reinforced by the movement of enemy troops towards the strongholds of the Qurayza. Muhammad became anxious about their conduct, and realised the grave potential danger the Qurayza posed. Because of his pact with the Qurayza, he had not bothered to make defensive preparations along the Muslims' border with the tribe. The Qurayza also possessed weaponry: 1,500 swords, 2,000 lances, 300 suits of armour, and 500 shields. Muhammad sent three leading Muslims to bring him details of the recent developments. He advised the men to openly declare their findings, should they find the Banu Qurayza to be kind, so as to increase the morale of the Muslim fighters. However, he warned against spreading the news of a possible breach of the pact on the Qurayza's part, so as to avoid any panic within Muslim ranks. The leaders found that the pact indeed had been renounced and tried in vain to convince the Qurayza to revert by