Musnad Ahmad 5:627

'Abd al-Razzaq narrated to us, Ma'mar informed us, from al-Zuhri, from Abu 'Ubayd, the freed slave of 'Abd al-Rahman ibn 'Awf, who said: Then I witnessed him [Ali] with Ali, and he prayed before he delivered the sermon, without an adhan or an iqamah, then he delivered the sermon. He said: "O people, the Messenger of Allah, may Allah bless him and grant him peace, has forbidden you from eating your sacrificial meat after three nights, so do not eat it after that."