Book 25, Hadith 61

It was narrated that Shurahbil bin As-Simt said:"I said: 'O 'Amr bin 'Abasah! Tell us a Hadith that you heard from the Messenger of Allah (ﷺ) without forgetting or omitting anything.' He said: 'I heard the Messenger of Allah (ﷺ) say: Whoever shoots an arrow in the cause of Allah, and it reaches the enemy, whether it misses or hits, it will be as if he freed slave. Whoever frees a believing slave, that will be a ransom for him, limb by limb, from the Fire of Hell. Whoever develops a gray hair in the cause of Allah, it will be light for him on the Day of Resurrection