Abu Hurairah reported,

The Messenger of Allah ﷺ said, "Horses bring reward to one man, a shield to another, and a burden upon a third.As for the one who earns reward, he is a man who keeps a horse for the sake of Allah and gives it a long tether in a meadow or a garden. Whatever it eats within the reach of that tether from the meadow or the garden is counted as good deeds for him. And if it were to break its tether and gallop up a rise or two, its hoofprints and its droppings would be good deeds for him. And if it were to pass by a river and drink from it while he had no intention of watering it, that too would be good deeds for him. So such a horse brings him reward.Then there is the man who keeps a horse to make himself self-sufficient and to spare himself from begging, and he does not forget the right of Allah concerning its neck or its back. For him the horse is a shield.And there is the man who keeps a horse out of pride, for show, and in hostility toward the people of Islam. For him the horse is a burden."The Messenger of Allah ﷺ was then asked about donkeys, and he said, "Nothing has been revealed to me about them except this all-embracing, singular verse, 'So whoever does an atom's weight of good will see it, and whoever does an atom's weight of evil will see it' [Zalzalah 99:7–8]."

عن أبي هريرة

أن رسول الله ﷺ قال: الخيل لرجل أجر، ولرجل ستر، وعلى رجل وزر، فأما الذي له أجر، فرجل ربطها في سبيل الله، فأطال لها فى مرج أو روضة فما أصابت في طيلها ذلك من المرج أو الروضة، كان له حسنات، ولو أنها قطعت طيلها ذلك، فاستنت شرفا أو شرفين، كانت آثارها وأرواثها حسنات له، ولو أنها مرت بنهر، فشربت منه ولم يرد أن يسقي به، كان ذلك حسنات له، فهى له أجر. ورجل ربطها تغنيا وتعففا، و لم ينس حق الله في رقابها ولا ظهورها، فهي لذلك ستر. ورجل ربطها فخرا ورياء ونواء لأهل الإسلام، فهي على ذلك وزر وسئل رسول الله ﷺ عن الحمر، فقال: لم ينزل علي فيها شيء إلا هذه الآية الجامعة الفاذة {فمن يعمل مثقال ذرة خيرا يره ومن يعمل مثقال ذرة شرا يره} [الزلزلة: ٧- ٨].