At the eve of the Battle of the Ditch there was only one settlement of the Jews in Madina, namely that of Banu Quraizah. They assured the Muslims of their loyalty, and entered into a fresh agreement whereunder they bound themselves to help the Muslims in the event of any attack on Madina. When the Battle of the Ditch began, they assured the Muslims that they would stand by them. They, however, avoided active assistance on one pretext or the other. In the course of the battle they acted treacherously. Huyayy b Akhtab the leader of Banu Nadir who had been expelled by the Muslims from Madina approached Banu Quraizah and prevailed upon them to cast in their lot with the Quraish and their confederates who were fighting against Islam. Banu Quraizah were heavily bribed by the Quraish and they undertook to assist the confederates in their action against the Muslims. The Holy Prophet sent Sa'ad b Muadh the chief of the Aus tribe to them to prevail upon them to bide by the their agreement which they had made with the Muslims. Confident of the victory of the confederates, the Banu Quraizah adopted a hostile attitude and declared that they knew of no treaty with the Muslims. At the stage it was not possible for the Muslims to take any action against the Jews, and the Holy Prophet chose to be quiet. It was because of the treachery of Banu Quraizah that some of the Quraish warriors were able to cross the ditch and challenge the Muslims to duel. When Ali killed Amr in single combat, and all the Quraish warriors who had crossed the ditch were forced to retreat, the Holy Prophet decided to keep a greater watch on the movements of the Banu Quraizah. When the Battle of the ditch began, the Holy Prophet shifted the women and children of Muslim families to safer quarters. The game of the Quraish was to have access to this quarter and carry away Muslim women and children as captives. Banu Quraizah undertook to help the Quraish. One day the Jews sent a spy to procure intelligence about the quarter where the Muslim women and children were lodged. Safia, an aunt of the Holy Prophet, saw the spy. She stealthily stole behind the spy, and struck a mortal blow at his head with a pole that she carried in her hand. Thereafter the Muslims strengthened the guard at the quarter. The Muslims had expelled the Banu Nadir from Madina after the Battle of Uhud and their leader Huyayy b Akhtab was a non-grate person for the Muslims. Banu Quraizah gave asylum to Huyayy who was an archenemy of the Muslims. During the course of the Battle of the Ditch, Banu Quraizah, at the instance of Huyayy, created difficulties for the Muslims.