The Prophet ﷺ ordered that Furat bin Hayan be killed, for he had been a spy for Abu Sufyan and was his ally. He passed by a circle of the Ansar and said, "I am a Muslim."They said, "Messenger of Allah, he claims to be a Muslim."The Prophet ﷺ replied, "Among you are some men whose faith we entrust to them. Furat bin Hayan is one of them."
حدثنا علي بن عبد الله حدثنا بشر بن السري قال أبو عبد الرحمن وحدثني أبو خيثمة حدثنا بشر بن السري حدثنا سفيان عن أبي إسحاق عن حارثة بن مضرب
أن النبي ﷺ أمر بقتله وكان عينا لأبي سفيان وحليفا فمر بحلقة من الأنصار فقال إني مسلم قالوا يا رسول الله إنه يزعم أنه مسلم فقال إن منكم رجالا نكلهم إلى إيمانهم منهم فرات بن حيان
Its isnad is sahih. Haritha bin Mudarrib is trustworthy, and Bukhari narrated from him. The hadith was narrated by Abu Dawud, 3/48, no. 2652, in the chapter on jihad, regarding the dhimmi spy, and Hakim graded it sahih, 2/115 and 4/369, and Dhahabi agreed with him in both places. Abu Naeem also narrated it in al-Hilyah, 2/18.