This excerpt is taken from Sheikh Abi Abdul Saboor Abdul Ghafoor Damni's book Fazail al-Jihad.
عن أبى بكر بن عبد الله بن قيس عن أبيه قال سمعت أبى وهو بحضرة العدو يقول قال رسول الله صلى الله عليه وسلم إن أبواب الجنة تحت ظلال السيوف فقام رجل رث الهيئة فقال يا أبا موسى أنت سمعت رسول الله صلى الله عليه وسلم يقول هذا قال نعم قال فرجع إلى أصحابه فقال أقرأ عليكم السلام ثم كسر جفن سيفه فألقاه ثم مشى بسيفه إلى العدو فضرب به حتى قتل
"Abu Bakr bin Abdullah bin Qais narrates from his father, saying: I heard my father in the presence of the enemy saying that the Messenger of Allah, peace be upon him, said: 'Indeed, Paradise lies under the shades of swords.' Upon hearing this, a poor, dirty, and shabby man stood up and said: O Abu Musa! Have you heard that the Messenger of Allah, peace be upon him, said this? He said: Yes. The man then went to his companions, greeted them, broke the sheath of his sword and threw it away, then took his sword and went towards the enemy and attacked them until he was martyred."
Reference: (Sahih Muslim)
Reference: (Narrated by Muslim: Book of Leadership, Chapter on the Proof of Paradise for the Martyr, Number: 1902)
Derived Benefits
➊ Imam Nawawi, may Allah have mercy on him, states that the meaning of ”ان ابواب الجنة تحت ظلال السيوف“ as explained by the scholars is that being present in the battlefield of jihad and fighting is the path to Paradise and the means of entering Paradise.
Reference: (Sharh Sahih Muslim)
➋ The zeal for jihad of a poor and humble companion is highly commendable, for when he became certain that ”ان ابواب الجنة تحت ظلال السيوف“ (the hadith) is the command of the Messenger of Allah, peace be upon him, then out of eagerness for Paradise, he immediately rushed to the battlefield without delay.
➌ Verifying the good deed: From the mentioned hadith, it is also understood that one should verify the desirable action, as when this person learned the saying of the Messenger of Allah, peace be upon him, ”ان الجنة تحت ظلال السيوف“ through Abu Musa, may Allah be pleased with him, he immediately asked Abu Musa, may Allah be pleased with him, with emphasis, "O Abu Musa! Did you really hear this from the Messenger of Allah, peace be upon him?"