Musnad Ahmad 31:686

'Affan narrated to us, Yazid ibn Zuray' narrated to us, Dawud narrated to us, from Abu Nadra, from Abu Sa'id, who said: We set out from Medina, shouting out the Hajj with a loud shout. When we arrived in Mecca, we performed Tawaf. He said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Make it an 'Umrah, except for whoever has the sacrificial animal with him." When it was the evening of the Day of Tarwiyah, we entered into the state of Ihram for Hajj.