Abu Bakr bin Abi Musa (may Allah have mercy on him) narrates from his father (may Allah be pleased with him) that when the enemy was present, he said: I heard the Messenger of Allah (peace and blessings be upon him) saying: "Paradise is under the shade of swords." A man stood up who was in a dishevelled state, and said: O Abu Musa! Did you yourself hear the Messenger of Allah (peace and blessings be upon him) saying this? He said: Yes. He went back to his companions, greeted them with salam, broke the scabbard of his sword, launched a fierce attack on the enemy and was martyred. [Sahih: Muslim]
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 17922