عبد الملك بن عمير قال شهدت علياً رضي الله عنه وأتى بأخي بني عجل المستورد بن قبيصة تنصر بعد اسلامه فقال له علي رضي الله عنه ما حُدِّثتُ عنك قال ما حدثت عني قال حدثت عنك أنك تنصرت قال أنا على فقال له علي وأنا على دين المسيح فقال له علي ما تقول فيه فتكلم بكلام خفيَ علي فقال علي طؤوه فوطئ حتى مات فقلت ل لذي يليني ما قال قال قال المسيح ربه
السنن الكبرى للبيهقي كتاب المرتد باب من قال في المرتد يستتاب مكانه فإن تاب وإلا قتل
‘Abd Al-Malik ibn ‘Umair said: I was with ‘Ali (may Allah be pleased with him), and he had brought a brother of mine from the Banu ‘Ijl, Al-Mustawrid ibn Qabisa, who had become a Christian after having been in Islam. ‘Ali (may Allah be pleased with him) said to him: What have I been told about you? He replied: What have you been told about me? ‘Ali said: I have been told that you have become a Christian. He said: I am in the religion of the Messiah. ‘Ali said to him: And I am in the religion of the Messiah. Then ‘Ali asked him: What do you say about him? And he said something that made ‘Ali’s face change. Then ‘Ali said: Trample him! So he was trampled on until he died. Then I asked the person close to me: What did he say? He replied: He said that the Messiah is his lord.
Al-Bayhaqi, Al-sunan Al-kubra [The Greater Compilation of Sunnah], The book of apostates, Section: those who say regarding apostates that they are to be called to repentance on the spot, and if they repent, fine, otherwise they are killed