Narrated Abdullah: The Prophet arranged for a horse race of the horses which had not been made lean; the area of the race was from AthThaniya to the mosque of Bani Zuraiq. (The sub-narrator said, "'Abdullah bin 'Umar was amongst those who participated in that horse race.").
— Sahih Bukhari, Volume 4, Book 52: Fighting for the Cause of Allah (Jihaad), Hadith #121