The Rites of Hajj (Kitab Al-Manasik Wa'l-Hajj)
Dawud :: Book 10 : Hadith 1914
Narrated Ibn Mirba' al-Ansari:
Yazid ibn Shayban said: We were in a place of stationing at Arafat which Amr (ibn Abdullah) thought was very far away from where the imam was stationing, when Ibn Mirba' al-Ansari came to us and told (us): I am a messenger for you from the Apostle of Allah (peace_be_upon_him). He tells you: Station where you are performing your devotions for you are an heir to the heritage of Abraham.