Musnad Ahmad #140

Faddalah bin 'Ubaid said: I heard 'Umar bin al-Khattab say that he heard the Messenger of Allah ﷺ say: `The martyrs are three; a man who believes and has good faith, who meets the enemy and shows sincerity to Allah until he is killed ­ he is the one to whom people will raise their heads on the Day of Resurrection` ­ and the ­­Messenger of Allah ﷺ raised his head until his hat or Umar's hat fell off - ; `and a man who is a believer and has good faith, who meets the enemy and it is as if his skin was beaten with the thorns of an acacia tree, then a stray arrow comes and kills him - he will be in the second rank; and a man who is a believer and has good faith, but he mixes good and bad deeds, and he meets the enemy and shows sincerity to Allah until he is killed - he will be in the third rank.`