The Prophet ﷺ said, "If somebody keeps a horse in Allah's Cause motivated by his faith in Allah and his belief in His Promise, then he will be rewarded on the Day of Resurrection for what the horse has eaten or drunk and for its dung and urine."
أَنَّهُ سَمِعَ أَبَا هُرَيْرَةَ ؓ يَقُولُ قَالَ النَّبِيُّ ﷺ مَنِ احْتَبَسَ فَرَسًا فِي سَبِيلِ اللَّهِ إِيمَانًا بِاللَّهِ وَتَصْدِيقًا بِوَعْدِهِ فَإِنَّ شِبَعَهُ وَرِيَّهُ وَرَوْثَهُ وَبَوْلَهُ فِي مِيزَانِهِ يَوْمَ الْقِيَامَةِ