Musnad Abu Ya'la al-Mawsili 111:113

Zuhayr narrated to us, Ahwas ibn Jawwab al-Dabbi narrated to us, Ammar ibn Zurayq narrated to us, from Sulayman al-A'mash, from al-Hakam, from Miqsam, from Ibn Abbas, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "The Dhuhr [prayer] on the Day of Tarwiyah and the Fajr [prayer] on the Day of Arafah are at Mina."