The Messenger of Allah ﷺ said, "The best of horses is the jet-black one with a white blaze on its forehead, a white upper lip, three white legs, and the right foreleg free of white markings. If not jet-black, then a dark bay with these same markings."
حدثنا حسن بن موسى حدثنا ابن لهيعة ويحيى بن إسحاق قال أخبرنا ابن لهيعة قال حسن في حديثه حدثنا يزيد بن أبي حبيب عن علي بن رباح
عن رسول الله ﷺ قال خير الخيل الأدهم الأقرح الأرثم محجل الثلاث مطلق اليمين فإن لم يكن أدهم فكميت على هذه الشية
Its chain of transmission is hasan. The hadith was narrated by Abu Dawud in the Book of Jihad, 3/22, no. 2543, and by Tirmidhi, 4/203, no. 1696, who said, "Hasan gharib sahih," in the Book of the Merits of Jihad, and by Nasai in the Book of Horses, 6/218, no. 3565, and by Ibn Majah, 2/933, no. 2789, and by Darimi, 2/131, and Hakim, 2/92, and Bayhaqi, 6/330.