I heard the Messenger of Allah ﷺ say: "Whoever shoots an arrow in the cause of Allah, then he has the reward of freeing a slave."
عَنْ أَبِي نَجِيحٍ السُّلَمِيِّ ؓ قَالَ سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ مَنْ رَمَى بِسَهْمٍ فِي سَبِيلِ اللَّهِ فَهُوَ لَهُ عَدْلُ مُحَرَّرٍ