Abd al-Rahman bin Ka'b bin Malik (may Allah have mercy on him) narrates from a Companion (may Allah be pleased with him) that in the story of Banu al-Nadir it is (mentioned) that they schemed against the Prophet (peace and blessings be upon him). The narrator says that in the morning the Prophet (peace and blessings be upon him) besieged them with an army and said to them: "You are not in a state of safety with me unless you remain upon this covenant of yours which you made with me." They refused to give a covenant, so he fought them. Then he went with the army towards Banu Qurayzah and left Banu al-Nadir. When he sought a covenant from Banu Qurayzah, they gave him a covenant; then he left Banu Qurayzah and went towards Banu al-Nadir. Then they agreed to go into exile. This was the covenant of Banu Qurayzah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجزية / 18855