What happened at Ghazwa Bani Quraydha.
Banu Quraydha betrayed the Muslims and breached the covenant which was concluded with the Muslims at a crucial time when they were besieged by 10,000 Kaafir fighters. Thus, they exposed the life of all the Muslims (men, women, children and elders) to danger if it was not for the Mercy and Grace of Allaah The Almighty Who repelled those who disbelieved in their rage.
Following is summary of Ghazwa Bani Quraydha taken from Al Bidaya wal Nihaya Vol 4 pages 94-100.
1. It is said that Prophet peace be upon him tried to talk with them peacefully but they replied, Do not waste your time. Huyayy ibn Akhtab encouraged them to fight against Muslims.
2. وكان علي قد سمع منهم قولا سيئا لرسول الله صلى الله عليه وسلم وأزواجه رضي الله عنهن، فكره أن يسمع ذلك رسول الله صلى الله عليه وسلم، فقال رسول الله صلى الله عليه وسلم: «لمَ تأمرني بالرجوع؟» فكتمه ما سمع منهم.
فقال: «أظنك سمعت فيَّ منهم أذى، فامض فإن أعداء الله لو رأوني لم يقولوا شيئا مما سمعت».
Ali ra heard bad words from them for Prophet peace be upon him and his wives, he disliked that Prophet peace be upon him would hear the same, He said to Prophet peace be upon him I am enough for these jews.
3. When the tribe of Bani Quraydha (who were planning to Kill the Sahaba and Prophet peace be upon him) was ready to accept Sad’s judgment, Sad came and sat beside Allah’s Apostle who said to him. “These people are ready to accept your judgment.” Sad said, “I give the judgment that their warriors should be killed and their children and women should be taken as prisoners.”