Musannaf Ibn Abi Shayba 28:1030

Yazid ibn Harun narrated to us, he said: Sa'id ibn Zayd informed us, from al-Zubayr ibn Khirrit, from Abu Labid, who said: The horses were sent out, and al-Hakam ibn Ayyub was over Basra. He said: So we went out to look at them, and we said: "If only we would turn toward Anas ibn Malik." So we turned toward him while he was in his palace in al-Zawiyah. We said to him: "O Abu Hamzah, did they use to bet on horse races during the time of the Messenger of Allah, may Allah bless him and grant him peace?" He said: "Yes, by Allah, the Messenger of Allah, may Allah bless him and grant him peace, bet on a horse called Subhah, and it came in first, so he was delighted by that."