Sunan Abi Dawud 4355
سنن أبي داود#4355SahihNarrated Mu'adh ibn Jabal: AbuMusa said: Mu'adh came to me when I was in the Yemen. A man who was Jew embraced Islam and then retreated from Islam. When Mu'adh came, he said: I will not come down from my mount until he is killed. He was then killed. One of them said: He was asked to repent before that
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautHasan
Zubair Ali ZaiIsnaad Hasan
In-book reference: 40:5