Al-Mu'jam al-Awsat 361 — he said: I heard the Messenger of Allah ﷺ

It is narrated from Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) that he said: I heard the Messenger of Allah (peace and blessings be upon him) saying: "The martyrs are of three kinds: A believer of firm faith who met the enemy and was true to Allah (in his pledge) until he was killed; this is the one towards whom people will raise their necks (to look at him, because of his lofty rank) on the Day of Resurrection. Second, a believer of firm faith who met the enemy and was struck by a stray arrow from an unknown direction which killed him; he is in the second rank. And third, a believer who had wronged himself (through sins), who met the enemy and was true to Allah until he was killed; he is in the third rank."
This hadith is narrated from Sayyiduna Umar (may Allah be pleased with him) only with this chain, and Ibn Lahi'ah (may Allah have mercy on him) is alone in narrating it.