Sahih Muslim Book 7, Hadith Number 3137.

Chapter : The Muhajir is permitted to stay for three days in Mecca after Hajj and Umra and not more than this.

Al-“Ala’ b. al-Hadrami reported Allah’s Messenger (may peace be upon him) as saying: The stay at Mecca after the completion of his rituals (of Hajj) is only for three days.