Ibn Ishaq reported,

Asim bin Umar bin Qatada related to me, from elders of his people, who said:When the Messenger of Allah ﷺ met them, he asked them, "Who are you?"They replied, "A group from the Khazraj."He asked, "Are you allies of the Jews?"They said, "Yes."He said, "Will you not sit so I may speak with you?"They replied, "Certainly."So they sat with him, and he called them to Allah the Mighty and Majestic, presented Islam to them, and recited the Quran to them.Among the things Allah brought about for them through Islam was this. The Jews lived alongside them in their land. The Jews were people of scripture and knowledge, while they themselves were polytheists and idol-worshippers. They had raided the Jews in their own territory, and whenever a dispute arose between them, the Jews would say to them, "A prophet is about to be sent, his time has drawn near. We will follow him and slaughter you alongside him just as Aad and Iram were slaughtered."So when the Messenger of Allah ﷺ spoke to that group and called them to Allah, they said to one another, "My people, by Allah, know that this is the very prophet the Jews have been threatening you with. Do not let them get to him before you."They responded to his call by believing him and accepting the Islam he presented to them. They said, "We have left behind our people, and there is no people among whom enmity and evil are as widespread as among them. Perhaps Allah will unite them through you. We will go to them and call them to your cause, and present to them this religion that we have accepted from you. If Allah unites them upon it, then no man will be mightier than you."Then they departed from the Messenger of Allah ﷺ, returning to their land as believers who had affirmed his truth.

عن ابن إسحاق قال

فحدثني عاصم بن عمر بن قتادة، عن أشياخ من قومه، قالوا: لما لقيهم رسول الله ﷺ قال لهم: من أنتم؟ قالوا: نفر من الخزرج، قال: أ من موالي يهود؟ قالوا: نعم، قال: أفلا تجلسون أكلمكم؟ قالوا: بلى. فجلسوا معه، فدعاهم إلى الله عزوجل وعرض عليهم الإسلام، وتلا عليهم القرآن. قال: وكان مما صنع الله بهم في الإسلام أن يهود كانوا معهم في بلادهم، وكانوا أهل كتاب وعلم، وكانوا هم أهل شرك وأصحاب أوثان، وكانوا قد غزوهم ببلادهم، فكانوا إذا كان بينهم شيء قالوا لهم: إن نبيا مبعوث الآن، قد أظل زمانه، نتبعه فنقتلكم معه قتل عاد وإرم، فلما كلم رسول الله ﷺ أولئك النفر، ودعاهم إلى الله، قال بعضهم لبعض: يا قوم، تعلموا والله إنه للنبي الذي توعدكم به يهود، فلا تسبقنكم إليه. فأجابوه فيما دعاهم إليه بأن صدقوه وقبلوا منه ما عرض عليهم من الإسلام، وقالوا: إنا قد تركنا قومنا، ولا قوم بينهم من العداوة والشر ما بينهم، فعسى أن يجمعهم الله بك، فسنقدم عليهم، فندعوهم إلى أمرك، وتعرض عليهم الذي أجبناك إليه من هذا الدين، فإن يجمعهم الله عليه فلا رجل أعز منك. ثم انصرفوا عن رسول الله ﷺ راجعين إلى بلادهم، وقد آمنوا وصدقوا.