"Whoever keeps a horse for the cause of Allah out of faith in Allah and believing the promise of Allah, its feed, water, urine and dung will all count as Hasanat in the balance of his deeds." (Using translation from Nasāʾī 3582)  

عَنْ رَسُولِ اللهِ ﷺ قَالَ «مَنِ احْتَبَسَ فَرَسًا فِي سَبِيلِ اللهِ إِيمَانًا بِاللهِ وَتَصْدِيقًا لِوَعْدِ اللهِ كَانَ شِبَعُهُ وَرِيُّهُ وَبَوْلُهُ وَرَوْثُهُ حَسَنَاتٍ فِي مِيزَانِهِ يَوْمَ الْقِيَامَةِ»