Muwatta Malik 1002

Yahya related to me from Malik from Nafi from Abdullah ibn Umar that the Messenger of Allah, may Allah bless him and grant him peace, held a race between horses which had been made lean by training, from al-Hafya to Thaniyatu-lWada. He held a race between horses which had not been made lean from the Thaniya (a mountain pass near Madina) to the mosque of the Banu Zurayq. Abdullah ibn Umar was among those who raced them