Narrated 'Aisha: (the wife of the Prophet) Allah's Apostle used to let his head in (the house) while he was in the mosque and I would comb and oil his hair. When in Itikaf he used not to enter the house except for a need.
— Sahih Bukhari, Volume 3, Book 33: Retiring to a Mosque for Remembrance of Allah (I'tikaf), Hadith #246