Musnad Ahmad 5:262

Qutaybah ibn Sa'id narrated to us, Layth ibn Sa'd narrated to us, from Ibn al-Had, from 'Abdullah ibn Abi Salamah, from 'Amr ibn Sulaym al-Zuraqi, from his mother, that she said: While we were in Mina, 'Ali ibn Abi Talib was on a camel, and he was saying: "Indeed, the Messenger of Allah, may Allah bless him and grant him peace, says: 'These are days of eating and drinking, so let no one fast.'" And he made the people hear.