Sahih Bukhari Volume 3, Book 27, Hadith Number 25.

Narated By Ibn Umar : Whenever Allah’s Apostle left for Mecca, he used to pray in the mosque of Ash-Shajra, and when he returned (to Medina), he used to pray in the middle of the valley of Dhul-Hulaifa and used to pass the night there till morning.