It is narrated from Sahl bin Abi Hathmah (may Allah be pleased with him) that the Messenger of Allah (ﷺ) began with the Ansar, and when they did not take oaths, he (ﷺ) returned the oaths to the Jews.
Hadith Referenceمسند الإمام الشافعي / كتاب العتق / 1677
Hadith Takhrijأخرجه مسلم ، القسامة والمحاربين باب القسامة (1669)۔