قَالَ الْحَارِثُ بْنُ مِسْكِينٍ قِرَاءَةً عَلَيْهِ وَأَنَا أَسْمَعُ، عَنِ ابْنِ وَهْبٍ، حَدَّثَنِي طَلْحَةُ بْنُ أَبِي سَعِيدٍ، أَنَّ سَعِيدًا الْمَقْبُرِيَّ، حَدَّثَهُ عَنْ أَبِي هُرَيْرَةَ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ مَنِ احْتَبَسَ فَرَسًا فِي سَبِيلِ اللَّهِ إِيمَانًا بِاللَّهِ وَتَصْدِيقًا لِوَعْدِ اللَّهِ كَانَ شِبَعُهُ وَرِيُّهُ وَبَوْلُهُ وَرَوْثُهُ حَسَنَاتٍ فِي مِيزَانِهِ ‏"‏ ‏.‏

It was narrated from Abu Hurairah that the Messenger of Allah said: "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." Translation Not Available

Book Ref: Sunan An Nisai Book 28 Hadith 3582
Web Ref:  Sunan An Nisai Vol 4 Book 28 Hadith 3612