The Prophet ﷺ said, "Whoever keeps a horse for the sake of Allah, out of faith in Allah and belief in His promise, then its feed, its water, its dung, and its urine will all be in his scale on the Day of Resurrection."
قال النبي ﷺ: من احتبس فرسا سبيل الله إيمانا بالله، وتصديقا بوعده؛ فإن شبعه وريه وروثه وبوله في ميزانه يوم القيامة.
Bukhari narrated it in the chapter on jihad and expeditions (2853), from Ali bin Hafs, who said, Ibn Mubarak told us, Talha bin Abu Saeed informed us, he said, I heard Saeed Maqburi narrating that he heard Abu Hurairah say, then he mentioned it.