Sayyiduna Abu Najih al-Sulami (may Allah be pleased with him) said: We besieged the fortress of Ta'if together with the Prophet (peace and blessings be upon him), and I heard the Messenger of Allah (peace and blessings be upon him) say: "Whoever shoots arrows in the path of Allah, they are equal to freeing a slave." On that day I shot sixteen arrows. I heard the Messenger of Allah (peace and blessings be upon him) saying: "Whoever shoots an arrow in the path of Allah will have a rank in Paradise; whoever grows grey in Islam, it will be a light for him on the Day of Resurrection; whichever Muslim frees a Muslim, Allah will save his limbs from Hell in return for his (the freed man's) limbs; and whichever Muslim woman frees a Muslim woman, Allah will free all of her limbs in return for all of her (the freed woman's) limbs."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب العتق / 21311