Abu Bakra reported,

The Prophet of Allah ﷺ passed by a man who was prostrating as he was on his way to the prayer. He completed the prayer and returned to find the man still prostrating. The Prophet ﷺ stood up and asked, "Who will kill this man?"A man stood up, rolled up his sleeves, drew his sword, and brandished it. Then he said, "Prophet of Allah, may my father and mother be ransomed for you, how can I kill a man who is prostrating, bearing witness that there is no god but Allah and that Muhammad is His servant and messenger?"Then the Prophet asked again, "Who will kill this man?"Another man stood up and said, "I will." He rolled up his sleeves, drew his sword, and brandished it until his hand trembled. Then he said, "Prophet of Allah, how can I kill a man who is prostrating, bearing witness that there is no god but Allah and that Muhammad is His servant and messenger?"The Prophet ﷺ then said, "By the One in whose hand is the soul of Muhammad, had you killed him, he would have been the first and the last of a great trial."

عن أبي بكرة

أن نبي الله ﷺ مر برجل ساجد، وهو ينطلق إلى الصلاة، فقضى الصلاة، ورجع عليه وهو ساجد، فقام النبي ﷺ، فقال: من يقتل هذا؟ فقام رجل، فحسر عن يديه، فاخترط سيفه وهزه، ثم قال: يا نبي الله، بأبي أنت وأمي، كيف أقتل رجلا ساجدا، يشهد أن لا إله إلا الله، وأن محمدا عبده ورسوله؟ ثم قال: من يقتل هذا؟ فقام رجل، فقال: أنا، فحسر عن ذراعيه، واخترط سيفه، وهزه حتى أرعدت يده، فقال: يا نبي الله، كيف أقتل رجلا ساجدا، يشهد أن لا إله إلا الله، وأن محمدا عبده ورسوله؟ فقال النبي ﷺ: والذي نفس محمد بيده لو قتلتموه، لكان أول فتنة وآخرها.