Musnad Ahmad 27:633

Isma'il narrated to us, from Ayyub, from Nafi', who said: When Ibn Umar would enter the nearest part of the Haram, he would cease the Talbiyah. Then he would come to Dhu Tuwa and spend the night there, and he would pray the morning prayer there, and he would perform ghusl. And he would relate that the Messenger of Allah (peace and blessings of Allah be upon him) used to do that.