Musnad Ahmad 779:1

Yahya ibn Sa'id narrated to us, from Hisham, Qatadah narrated to us, from Salim ibn Abi al-Ja'd, from Ma'dan ibn Abi Talhah, from Abu Najih al-Sulami, who said: We besieged the fortress of Ta'if, or the palace of Ta'if, with the Messenger of Allah, peace and blessings of Allah be upon him. He said: "Whoever reaches [the target] with an arrow in the way of Allah, the Exalted and Majestic, he has a degree in Paradise." I reached [the target] that day with sixteen arrows. "And whoever shoots an arrow in the way of Allah, the Exalted and Majestic, it is for him equivalent to freeing a slave. And whoever grows gray in the way of Allah, the Exalted and Majestic, it is a light for him on the Day of Resurrection. And any man who frees a Muslim man, Allah, the Exalted and Majestic, will make a protection for every bone of his bones from the bones of the one he freed against the Fire. And any Muslim woman who frees a Muslim woman, Allah, the Exalted and Majestic, will make a protection for every bone of her bones from the bones of the one she freed against the Fire."