Sunnan Abu Dawud Collection: ::Book Number 14:: Hadith # 2538
Narrated AbuWahb: The Prophet (peace_be_upon_him) said: Keep to every sorrel horse with a white blaze and white on the legs, or dark bay with a white blaze. He then mentioned something similar. Muhammad ibn al-Muhajir said: I asked him: Why was a sorrel horse preferred? He replied: Because the Prophet (peace_be_upon_him) had sent a contingent, and the man who first brought the news of victory was the rider of a sorrel horse.