Musnad Abu Ya'la al-Mawsili 154:104

Zuhayr narrated to us, Waki' narrated to us, Nafi' ibn 'Umar al-Jumahi narrated to us, from Sa'id ibn Hassan, from Ibn 'Umar: That the Messenger of Allah (may Allah bless him and grant him peace) used to encamp at Arafat in Wadi Namirah.