Uqba bin Malik reported,

The Messenger of Allah ﷺ sent out a military expedition. The detachment raided a people, and one man broke away from them. A man from the expedition pursued him with his sword drawn. The fleeing man said, "I am a Muslim," but the pursuer paid no attention to what he said and struck him down, killing him.News of this reached the Messenger of Allah ﷺ, and he spoke harshly about it. Word of his rebuke reached the killer.While the Messenger of Allah ﷺ was delivering a sermon, the killer said, "Messenger of Allah, by Allah, he only said what he said seeking refuge from being killed."The Messenger of Allah ﷺ turned away from him and from those before him among the people and continued his sermon. Then the man spoke again, "Messenger of Allah, he only said what he said seeking refuge from being killed."Once more the Messenger of Allah ﷺ turned away from him and from those before him among the people and continued his sermon. But the man could not contain himself, and a third time he said, "Messenger of Allah, by Allah, he only said it seeking refuge from being killed."The Messenger of Allah ﷺ then turned to him, the displeasure visible on his face, and said to him, "Allah has refused to allow me to kill a believer."

عن عقبة بن مالك قال

بعث رسول الله ﷺ سرية، قال: فأغارت على قوم، قال: فشذ من القوم رجل، قال: فأتبعه رجل من السرية شاهرا سيفه، قال: فقال الشاذ من القوم، إني مسلم، قال: فلم ينظر فيما قال، فضربه فقتله، قال: فنمي الحديث إلى رسول الله ﷺ، قال: فقال فيه قولا شديدا، فبلغ القاتل، قال: فبينا رسول الله ﷺ يخطب إذ قال القاتل: يا رسول الله، والله ما قال الذي قال إلا تعوذا من القتل. قال: فأعرض عنه، وعمن قبله من الناس، وأخذ في خطبته، ثم قال أيضا: يا رسول الله، ما قال الذي قال إلا تعوذا من القتل. فأعرض عنه وعمن قبله من الناس وأخذ في خطبته، ثم لم يصبر، فقال الثالثة: يا رسول الله، والله ما قال إلا تعوذا من القتل. فأقبل عليه رسول الله ﷺ- تعرف المساءة في وجهه. فقال له: إن الله عز وجل أبي علي أن أقتل مؤمنا.