It is narrated from Hazrat Miqdad bin Amr (may Allah be pleased with him) that once I submitted in the presence of the Messenger of Allah, "O Messenger of Allah! Tell me, if a man attacks me with a sword and cuts off my hand, then seeks shelter behind a tree to save himself from me, and at that moment recites 'La ilaha illallah,' can I kill him?" The Noble Prophet (peace and blessings be upon him) said, "No." I repeated my question two or three times, and the Noble Prophet (peace and blessings be upon him) said, "No, otherwise, before he recited the Kalimah, you would become like he was, and he would become as you were before this incident."