Idolator enemies of Muslims under the leadership of Khalid bin Walid (then Atheist/Idolator)
attacked Prophet and injured his face. Prophet's face was bleading and he said,"How can Allah guide the people who filled face of their Prophet from his own blood. In reply Allah says, "It is not for Prophet to say, whom Allah will guide or not guide". Shortly after this war,Khalid bin Walid rode to Madina by himself, set in front of Prophet SAW in Masjid-e-Nabvi, took Shahadah and became the greatest soldier/commander of Muslims. Prophet said to him, now your title is Saifullah from now on. By the time he retired from fighting wars , there was hardly any section of his body that did not have scars of wounds from fighting in battles after taking Shahadah. KhalidBin Walid always wished to die fighting for Allah, but because his title was Saifullah (Sword of Allah) he never died in Battle field. His death came from age and natural causes in his house.