(104) باب عَلَى مَا يُقَاتَلُ الْمُشْرِكُونَ
Al Miqdad bin Al Aswad reported that he said "Apostle of Allaah(ﷺ) tell me if I meet a man who is a disbeliever and he fights with me and cuts off one hand of mine with the sword and then takes refuge by a tree and says "I embraced Islam for Allah's sake. Should I kill him, Apostle of Allaah(ﷺ) after he uttered it (the credo of Islam)? The Apostle of Allaah(ﷺ) said "Do not kill him". I said "Apostle of Allaah(ﷺ), he cut off my hand. The Apostle of Allaah(ﷺ) said, Do not kill him. I f you kill him, he will become like you before you kill him and you will become like him before he uttered his credo which he has uttered now.
Reference: Sunan Abi Dawud 2644
In-book reference: Book 15, Hadith 168
English translation: Book 14, Hadith 2638