Miqdad bin Amr reported,

He said, "Messenger of Allah, I encountered a disbeliever and we fought. He struck my hand with his sword and cut it off, then he took refuge from me behind a tree and said, 'I have submitted to Allah.' Should I kill him after he has said this?"The Messenger of Allah ﷺ replied, "Do not kill him."He said, "Messenger of Allah, but he cut off one of my hands, and only said this after he had severed it. Should I kill him?"He answered, "Do not kill him. If you kill him, he will be in the position you were in before you killed him, and you will be in the position he was in before he uttered the words he spoke."

Bukhari 6865

Sahih

حدثنا عبدان حدثنا عبد الله حدثنا يونس عن الزهري حدثنا عطاء بن يزيد أن عبيد الله بن عدي حدثه

أن المقداد بن عمرو الكندي حليف بني زهرة حدثه وكان شهد بدرا مع النبي ﷺ

أنه قال يا رسول الله إني لقيت كافرا فاقتتلنا فضرب يدي بالسيف فقطعها ثم لاذ مني بشجرة وقال أسلمت لله آقتله بعد أن قالها قال رسول الله ﷺ لا تقتله قال يا رسول الله فإنه طرح إحدى يدي ثم قال ذلك بعد ما قطعها آقتله قال لا تقتله فإن قتلته فإنه بمنزلتك قبل أن تقتله وأنت بمنزلته قبل أن يقول كلمته التي قال

البخاري 6865صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Blood money
Chapter
Allah's saying, "And whoever kills a believer intentionally, his recompense is Hell"
Numbering
Darussalam 6865
Bukhari 6865