Musnad Ahmad 284:10

Ya'qub ibn Ibrahim narrated to us, he said: My father narrated to us, from Ibn Ishaq, he said: Wahb ibn Kaysan, the freed slave of the family of al-Zubayr, narrated to me, he said: I heard Abdullah ibn al-Zubayr on the day of the Eid saying, when he prayed before the sermon, then stood to address the people: "O people, this and that is the Sunnah of the Messenger of Allah, may Allah bless him and grant him peace."