Sahih Muslim Book 7, Hadith Number 2891.

Chapter : Excellence of spending the night at Dhi-Tuwa for entering Mecca (for Hajj) and getting into it after a bath and entering during the day.

Abdullah (b. ‘Umar) reported that whenever Allah’s Messenger (may peace be upon him) entered Mecca, he got down at Dhi Tuwa and spend the night there until he observed the dawn prayer. And Allah’s Messenger (may peace be upon him) observed this prayer on a rough hillock, and not in the mosque which had been then built there, but to the lower side of it (the mosque) on a hillock.