The Beloved Prophet Muḥammad, got upset with our master Usama ibn Zaid -the beloved, and the son of the beloved. One day, Usama was on the battlefield engaged with the enemy. During the heat of the battle one of the enemies slipped and fell, so Usama lifted his sword to strike him. At that very moment, the enemy shouted out:
"La 'ilaha 'illallah, Muḥammad rasulullah". -There's no god but Allah, Muḥammad is the messenger of Allah.
Yet, Usama struck and killed the man. When the Prophet got heed of this he condemned Usama, with anger visible on his face, he asked, "Did you kill him after he said that!?". Usama replied, "Oh Messenger of Allah, he only said it out of fear of the sword". But the Prophet Muḥammad quickly replied, "Did you look into his heart, oh Usama!?"